The age of the sisters is 37 years old, 3 years later, the elder sister is 3 years older than the yo

Sister: 20, Sister: 17, Sister is three years older than Sister and has been three years older, so the age of Sister is (37-3) 2, and then count the age of Sister.

My sister is 19 and my sister is 18 years old.

False color sister is unknown x sister is unknown y

So. x+y=37

3x-3y=3 then we get ===》 6x=114 so x=19 y=18

Thus it follows that the older sister is 19 years old and the younger sister is 18 years old.

Five years later, my sister was 4 years older than my sister. This year, my sister is also 4 years older than my sister.

Let the age of the younger sister be xThe age of the sister is 4+x

x+4+x=40

2x=36x=18

My sister is 18 years old.

My sister is 22 years old.

Sister 20, sister 17

My sister is always three years older than my sister, so after 3 years, I am suggesting that my sister is now three years older than my sister.

After 3 years, my sister is 3 years older than my sister There is a problem with this sister My sister is 3 years older than my sister and will always be 3 years older How many years is it 3 years older What is 3 years later?

Let's say the sister is x, and the sister is y

x＋y＝37（1）

x y 3 (2) then 1 2 for.

2x＝40 ，x＝20

y＝17

The age they chose to be in.

Sister 23, sister 20

My sister is six years older than my sister, and three years ago, my sister was three times older than my sister, and this year my sister is 12 years old.

Three years ago, my sister was three times older than my sister, and (my sister was twice as old as my sister) My sister was six years older than my sister, which corresponds to twice as much. (Corresponding to the ability to divide) 6 divided by 2 equals 3

Three years ago, my sister was three years old, and my sister was nine years old.

This year's sister is 9 + 3 = 12 (sentenced to be old).

Let the age of the sister be x and the age of the younger sister be y

x-y=6x-3)/(y-3)=3

The two types are combined, and the credible potato is sold by the hand x=12

So my sister is 12 years old this year.

According to the inscription column:

Sister - Sister = 6, Sister = Sister Na False Answer Sister Yuhui +6

Sister -3) = 3 (sister -3).

Sister +3 = 3 Sister -9

2 sisters = 12

Sister = 6 years old, sister = 12 years old, hopefully, thank you.

This is the mathematical letter rotten formula to imitate, x-y=6(x-3) (y-3)=3 two slippery silver leakage coupling, you can get x=12, so my sister is 12 years old this year. That's about the age.

My sister is 6 years older than my sister, three years ago, my sister's age was three times that of my sister, and Que Wan was twice as old as my sister, that is, 6 years old is twice the age of Zheng Zheng's sister, so three years ago my sister was 3 years old, my sister was 9 years old, and this year Sister Cong Shu is 12 years old. This question is relatively simple.

According to the title, the younger sister is a year old this year, and the sister's hole file is (a+6) years old, and because the sister's age three years ago was 3 times that of the younger sister, the sister was (a+6)-3 years old 3 years ago, and the younger sister was (a-3) years old, so (a+6)-3=3x(a-3).。。The solution gives a=6, so a+6=6+6=12. The answer is that my sister is 12 years old this year.

I hope I help you!!

The age difference between the sisters remains the same.

Set this year's sister to let the spine seep at the age of x.

x－3＝3x（x－3－6）

x－3＝3x（x－9）

x－3＝3x－27

3x－x＝27－3

2x＝24x＝12

A: This year, Sister Tan shouted that Sister Xing is 12 years old.

In this question, you can first set the younger sister to be x years old, then the sister Zhongchun sister is now x + 6 years old, and you can get the shirt to the following equation:

x+6-3=（x-3）*3

x+3=3x-9

2x=3+9

x=12/2

x = 6 (years or not).

6+6=12 (years).

A: My sister is 12 years old this year.

Let my sister be x years old three years ago, according to the meaning of the title, there is 3x-x=6, from this, x=3, air disturbance hail is three years ago, my sister Li Zaomei is 3 years old, and my sister is 9 years old, so this year's sister has Doufan 12 years old.

Ahem, the next tirade is the proof process, don't see it and cross it away, and in the end I will say the answer.

Solution: Let the age of the younger sister be x, and the age of the side sister Senqiang sister is x 6x 6 3 x and the solution x is 3

3 3 6 12 (years old) noisy.

That is, my sister is 6 years old this year, and my sister is 12 years old today.

My sister's age is three times that of my sister, so at this time my sister is 9 years old and my sister is 3 years old, which was three years ago, so my sister is 12 years old this year.

Season. What are the first three years of a six-year-old? It should be my sister 19 years old now, and my sister is. 55 years old, my sister is my sister is nine years old, isn't this six years older?

6 (3-1).

II. 6 2 II. 3 (years old) Na Shi.

3x3 II 9 (years).

9. Ten holes sedan 3 = 12 (years old and celebrated).

A: My sister is 12 years old this year.

My sister is 6 years older than my sister, and my sister was three times older than my sister three years ago, how old is my sister this year? This year, my sister is still three times as big as my sister.

My sister is three years older than my sister, and then six years ago I was twice as old as my sister, and at this time, I think six years ago was twice as old, so it means that when I was three years old, the other sister was six years old. So, since Ranqiao was six years ago, now one of them is nine years old and the other is 12 years old. So my sister is 12 years old.

Three years ago, my sister was 3 years old, my sister was 9 years old, my sister was 6 years older than my sister, and my sister was 3 times the age of my sister.

This year: My sister is 6 years old and my sister is 12 years old.

Three years ago, sister's age: 6 (3-1)=3 (years).

This year's sister: 3+3=6 (years old).

Sister of the current Qi year: 6 + 6 = 12 (years old).

My sister is 12 years old.

You might as well assume that your sister is x years old this year.

It is known from the title Oak Banquet Liang Lead that my sister is Xiangling X-6 years old this year.

Three years ago, my sister was x-3 years old and my sister was x-9 years old.

Therefore, the equation can be listed: x-3 3 (x-9).

Solution: x 12

So my sister is 12 years old.

My sister is 9 years old, so I don't know much.

If the elder sister is x, then the younger sister is x-3

5 years is a disguise, you don't need to look at it, no matter how many years, even if it is 1000 years later, my sister is still 3 years older than my sister! ）

x+（x-3）=37

2x=40x=20

x-3=17

So sister 20, sister 17

If the elder sister is x, then the younger sister is x-3

x+（x-3）=37

2x=40x=20

x-3=17

So sister 20, sister 17

General solution of binary linear equations:

Elimination: Eliminate the number of unknowns in the equation system from more to less, and solve them one by one.

There are two ways to eliminate the element:

1. Substitute the elimination element.

Example: Solve the system of equations x+y=5 6x+13y=89 Solution: Bring in by x=5-y, get 6(5-y)+13y=89, and solve y=59 7

Bring y=59 7 to get x=5-59 7, i.e. x=-24 7x=-24 7, y=59 7

This solution is the substitution method of elimination.

2. Addition and subtraction.

Example: Solve a system of equations x+y=9 x-y=5

Solution: + gives 2x=14, i.e. x=7

Bring x=7 into to get 7+y=9, and solve y=2

x=7，y=2

This solution is the method of addition and subtraction.

If my sister was x years old 5 years ago, then my sister was x + 3 years old 5 years ago.

Sister age + sister age = 37 years old, i.e. x + x + 3 = 37 solution x = 17 then x + 3 + = 20

My sister's current age: 17+5=22

My sister's current age: 20+5=25

First of all, the age difference remains the same, that is, the current age difference is also 3 years, so: (23+3) 2=13, 23-13=10

and times the problem. According to the title, the age of the sisters this year is 30-3 2 = 24 years old.

And my sister's age is 2 times that of my sister.

Sister's age = sum (multiple-1).

30-3 2) (Trousers 2+1).

8 (years old) The age of the sister is 8 2 = 16 (years old).

30-3x2）÷（1+1/2）

24x2/3

16 (years old) 16 2 = 8 (sophora cherry years old).

Answer: Sister Sanheng is now 16 years old, and my sister is now 8 years old.

Set my sister is now x years old, my sister is 2x years old, three years later, the code is resistant to travel x+3+2x+3=30, and the late sales solution is x=(30-6) 3=8, and the mu is thick to the sister who is 8 years old this year.

3 years to let the elder sister 15, sister 11

Set my sister now x, and my sister is now teasing Hu Y

x+y+6=26

x=(y-x)Hill Slide*2

Just find the equation.

Three years later, Sister 15 and Sister 11 assume that Sister Liang Shou is now X, and Sister is now Yx+Y+6=26x=(Y-X)*2, and then find the equation.

25 years old. According to the age and age of the sisters and sisters this year is 33 years old, we can find the actual age of the sisters and sisters 4 years ago, according to the formula: 33-8=25, and finally we get the age of the sisters and sisters four years ago and 25 years old.

My sister is 7 years older than my sister.

The age difference between the two people remains the same.

After 20 years, the younger sister is 3 + 20 = 23 years old, the sister is 3 + 7 + 20 = 30 years old, and 30-23 = 7 years old.

My sister is 3 years old this year, and my sister is seven years older than my sister;

After 20 years, my sister is older (7) years older than my sister;

The age difference is the same.

Summary. Set sister x, sister y

x+4=3y one.

x-7=y+9 two.

One minus two. 11=2y-9

2y=20y=10

x=3×10-4

x=26.My sister's age is 3 times younger than my sister's age by 4 years, my sister was the same age as my sister 7 years ago and my sister was 9 years ago, how old are my sister and sister now?

You're wrong about this, my sister couldn't be the same age as my sister seven years ago and my sister nine years ago. My sister is already old, and it stands to reason that my sister was older than my sister Lu Shi nine years ago. 樂樂

9 years later. My sister is 26 years old and my sister is 10 years old.

Set sister x, sister y

x+4=3y

x-7=y+9

Subtract the following formula from the above formula.

It can be concluded that y=10

Then we substitute y equal to 10 into the first formula, x=3 10-4x=26If you don't understand the dialect, please speak Mandarin or send text.

Set the sister x, the sister yx+4=3y, a x-7=y+9, the second pena, a dusty and unsubtracted tomb, and rush to the second 11=2y-9 2y=20y=10x=3 10-4x=26

Sister Xiaobei + sister 34 (the age difference is constant).

Sister Roll Pretending to Be Sister - Sister 2 So this year Sister 18 Sister Dasheng Stove Sister 16