Ask for help to solve a few simple binary equation problems

Let's say A walked x kilometers and B walked y kilometers.

x/3+y/4=54/60 ⑴

x/5+y/4=42/60 ⑵

Obtained by *60.

20x+15y=54 ⑶

Obtained by *60.

12x+15y=42 ⑷

3-4 got. 8x=12

x=Substitute x= into 3

y=y=x+y=

Solution: Let 30% of the potion take x kg, 75% of the potion take y kg, x+y=18 ......1)

2) y=18-x from (1) and substituting (2) to obtain.

9x/20=9/2

x=10 x=10 is substituted into 1y=8

Let the speed of the aircraft be x and the wind speed be y

x+y]* 1

x-y]*10/3=1200 ……2

Simplify. x+y=480 ……3

x-y=360 ……4

3-4 got.

2x=840

x=420 substitute x=420 into 3

y=60x=420

y=60

Let the uphill road from A to B be x and the downhill road be y

Then: x 3 + y 4 = 54 60 = 9 10 (1) x 4 + y 3 = 42 60 = 7 10 (2)2)*4 - 1)*3 get:

4y 3 - 3y 4 = 1 10 ==> y=6 35, so x = 18 7

The others are the same.

1.The downhill speed was not told.

kg，75%--y kg

x+y=18

x=10 y=8

3.Aircraft x km h, wind y km h;

x+y)x-y)10/3=1200

x=420 y=60

1.The title is not very clear.

The exponent of x,y is 1

2m+5n+9=1

4m-2n-7=1

Find m,n and substitute m,n into (n+1) m+2002 to get the answer 2. （1）

4k+b=-2

2k+b=-5

b=-4k=1/2

2) When x=8, y=1 2*8-4=0

3）3=x/2-4

x=173。

2a+3b+4=0

a-2b+1=4

Solve systems of equations. 2a+3b=-4

2a-4b=6

a=1，b=-2

Answer: A total of 10 teams participated in the competition.

Explanation: Assuming that there are x teams participating in the competition, then a total of 45 games are required for every two teams to play a game, x*(x-1) 2=45, simplified to (x-10)*(x+9)=0, x1=10, x2=-9 (rounded), so x=10

It's possible that I'm wrong, uh, or I'm stupid, it's supposed to be a game between every two teams, so the answer should be 14 games, with x teams.

x（x-1）/2=91

x1 = 14 x2 = -13 (round).

14 teams.

Solution: Suppose there are x teams participating in the competition.

91-1÷2=x

x=90÷2

x=45 (team).

60x+80y=132, according to the conditions of your problem, this is an indefinite equation to find the solution of integers.

Sorted x = 22-4y 3, from x 0 to get y 16, x is an integer, y is a multiple of 3, so y can go to the value of 3, 6, 9, 12, 15

The corresponding values of x are 18, 14, 10, 6, 2

1.Let's assume that the total number of saplings is x.

Then the first shift takes: 100+ (x-100) 10 The second shift takes: 200+ {x-200- 100+ (x-100) 10 } 10

Since the saplings are equal in each class, so:

100+ (x-100)/10=200+｛x-200-［100+ (x-100)/10］｝/10

Solve x=8100

So the total number of saplings is 8,100.

The first shift takes: 100+ (8100-100) 10 = 900 trees.

So the number of classes is 9.

2.Suppose a notebook with a unit price of yuan buys x copies, then the unit price of a laptop is yuan and you buy (36-x) copies.

Xiao Zhao gave his 2 yuan to Xiao Chen, and what he actually got back was (yuan. Then it took to buy a book according to what is known, and the equation can be obtained:

Solve x=24

Therefore, if you buy 24 notebooks with a unit price of yuan, you will buy 12 books with a unit price of yuan.

If the retrieved element is a decimal, the value of x is solved by substituting the equation with a decimal number, and the number of the book should be an integer, so it is impossible.

(1) Option 1. It is 8 meters long and 8 meters wide.

Option II. It is 4 meters long and 16 meters wide.

Option III. It is 2 meters long and 32 meters wide.

2) No, you can't. Because the largest area of the rectangle with the same circumference is the rectangle (i.e., square) with equal length and width, the area of the rectangle with equal length and width can only be increased by 1 square meter compared to the rectangular flower bed planned by the school.

1.It is required to build 9*7+1=64 square meters.

1. 32*2=64 square meters.

2. 16*4=64 square meters.

Three square meters.

2) No, you can't.

1. Let the lengths of the two right-angled sides be x and y respectively

The hypotenuse midline of RTΔ is equal to half of the hypotenuse.

The midline of the hypotenuse is 1 long

The length of the hypotenuse is 2x+y=2+6 -2=6

y=√6-x

Pythagorean theorem x +y =2 =4

x²+(6-x)² =4

The solution gives x=( 6+ 2) 2 y=( 6- 2) 2 or x=( 6- 2) 2 y=( 6+ 2) 2 The length of the three sides is ( 6+ 2) 2 ; (6-√2)/2；22. Set the walking speed of Class A to be x kilometers per hour.

The speed of class B is x+6 km/h.

According to the title: 10 x - 10 (x+6)=1+1 2x +6x-40=0

x+10)(x-4)=0

x=4 or x=-10 (rounded).

A--

I'll do it, but I don't have time to tell you sorry.

1) 14000 (1 x) = 12600, x = root number.

Closed sail 2) will, finger grip Weiqing 14000 (1 root number.

AX, BY, C, 50-x-y

1500x + 2100 + 2500*（50-x-y）= 90000

Finishing up to 10x + 4y = 350

x and y are both integers, and substituting them to satisfy the above equation, and x + y < 50 meet the above conditions of the three sets of data are the three sets of schemes.

The starting price is X yuan. The unit price of the taxi is y yuan, x+(11-3)*y=17,--1), x+(23-3)*y=35,--2), 2)-(1) to get 12y=18, y=yuan), substitute (1) to get x=5 yuan.

Suppose the taxi fare starts at x and the fare per kilometer is y, and the equation is as follows:

A: x+(11-3)y=17

B: x+(23-3)y=35

Solution: x=5 y=

Therefore, the starting fare of a taxi is 5 yuan, and the fare per kilometer is yuan.

Solution: Let the starting fare of the taxi be the source of x, and the yuan per kilometer after more than 3,000 kilometers is derived from the title: x+(11-3)y=17

x+（23-3）y=35

Solution: x=5 y=

Taxi fares start at 5 yuan and pay per kilometer after 3 kilometers.