Solve Primary 4 math problems, solve Primary 4 math problems

689-572 = 117 (yuan) to get a basketball and a volleyball **, 572-390182 (yuan) to get two basketballs and a volleyball **, a basketball and a volleyball ** and two basketballs and a volleyball **, that is, the price of a basketball: 182-117 = 65 (yuan).

** of a basketball and a volleyball minus ** of a basketball, that is, ** of a volleyball: 117-65 = 52 (yuan).

390-2 (65+52)=156 (yuan) is the price of two soccer balls, 156 2=78 (yuan) the price of one soccer ball.

First of all, we know that a basketball plus a volleyball is 689-572 = 117 (yuan), and we know that a volleyball plus a basketball and a football are 390 2 = 195 (yuan), then football is 195-117 = 78 (yuan).

Then multiply the sum of basketball and volleyball by 3, plus soccer multiplied by 2572-117*3-78*2=66 (yuan), which is basketball.

Finally, 195-66-78 = 51 (yuan) is volleyball.

The unit price of basketball is X yuan, volleyball is Y yuan, and football is Z yuan.

2x+2y+2z=390,4x+3y+2z=572,5x+4y+2z=689

The solution is x=65, y=52, z=78

Basketball is 65 yuan, volleyball is 52 yuan, and football is 78 yuan.

Solving a system of equations won't? ~

The unit prices of basketball, volleyball and football are x, y and z yuan respectively.

A system of column equations. 2x+2y+2z=390

4x+2y+3z=572

5x+4y+2z=689

Just answer it

How about going to 5th grade! I'm still in my third year of high school.

I'm not very good at pixels. If you don't understand, I'll tell you.

I would because I'm in fifth grade.

There is no need for an equation.

The younger brother and older brother add up to 32 + 28 = 60 books.

Ask for twice as many books for the younger brother as for the older brother.

So suppose the book is divided into three parts (20 copies each).

The younger brother had to take two copies, which was 40 copies.

And now the younger brother has 32 copies, 40 - 32 = 8, and the elder brother can give the younger brother 8 copies.

1. There is an isosceles triangle vegetable field, the bottom edge is 12 meters long, 2 meters shorter than the waist, find the perimeter of this vegetable field.

Waist: 12 + 2 = 14 (m).

Circumference: 14 2 + 12 = 40 (m).

A: The circumference of this vegetable plot is 40 meters.

2. Isosceles triangle, the top angle is 96 degrees, what is a base angle?

A: One bottom angle is 42 degrees.

Look!! tat

1) Waist: 12 + 2 = 14 (m).

The circumference of the isosceles triangle is 2 waist + base.

14×2+12=40(m)

2) Because it is an isosceles triangle, the two sides are equal and the two base angles are equal.

If one apex angle is known, then the two base angles are 180 (sum of the inner angles of the triangle) -96 = 84° 84 is the two base angles, and one base angle is 84 2 = 42°

The bottom length is 12 meters, 2 meters shorter than the waist, and the waist length: 12+2 14 meters.

Circumference of vegetable plots: 12 + 14 + 14 40 meters.

The apex angle is 96 degrees, and the waist angle is (180 96) 2 42 degrees.

12 + 2 = 14 meters.

12 + 14 * 2 = 12 + 28 = 40 meters.

A: The circumference of this vegetable plot is 40 meters.

180 degrees-96 degrees) 2=84 degrees 2=42 degrees.

A: One bottom angle is 42 degrees.

Don't blame me if you're wrong!!

Solution: 12+2 (12+2).

40 (m) A: The circumference of this vegetable plot is 40 m.

One bottom angle is 69 degrees.

First find that its waist is 12 + 2 = 14 (m), and its circumference is 14 + 12 + 14 = 40 (m). Since the sum of the inner angles of the triangle is 180 degrees, we know that the top angle is 42 degrees, so the ground angle is (180-42) 2=69 (degrees).

Question 1 12 + 2 = 14 meters 14 + 14 + 12 = 40 meters Question 2 The two angles of an isosceles triangle are equal 180-42 2 = 69 degrees.

180-96) 2 = 42 degrees.

The two base angles of an isosceles triangle are equal.

Solution: The waist of this vegetable plot is 12+2=14 meters.

The circumference is 14 + 14 + 12 = 40 meters at the waist and the bottom side.

Answer: The circumference of the vegetable patch is 40 meters.

1.Adding a 0 between two digits of a two-digit number gives a three-digit number that is 9 times that of the original two-digit number, what is the original two-digit number?

Let the two-digit number be ab, then there is: ab+a0b=ab0; 2b=10;b=5,a+1=b,a=

2.If the product of the sum of two numbers and the difference between them is 77, what are each of these two numbers?

Let these two numbers be ab; (a+b)*(a-b)=77, then there is: a+b=11, a-b=7, solve the equation, a=9, b=2

3.Lin Li's ten-digit and single-digit age swapped places this year, which happened to be her age of 18 years, how old she is this year.

Lin Li's age this year is ab:

Ba = Ab + 18, Analysis: A2, 8 + B = 10 + A, that is, B = A + 2, this question has more than one answer, all meet the requirements of B> = 2, B = A+2, that is, A = 1, 2, 3, 4, 5, 6, 7 can meet the requirements, this question has more than one answer, should be 7, respectively, 13, 24, 35, 46, 57, 68, 79.

1.Let the ten digits be x and the single digits be y

Then this number is 10x+y

Add 0 to 100x+y

Because 100x+y=9(10x+y).

The solution gives 10x=8y, i.e., 5x=4y

Because x,y is 0-9So x=4 y=5

2.Let x,y

x+y)（x-y)=77

The method for elementary school should be x=9 when only y=0 , 1,2 satisfies (x+y)(x-y)>=77 holds.

Try out x=9 y=2

3.As in question 1. Let the ten digits be x, and the single digits will be y10x+y+18=10y+x

The solution yields 9y-9x=18

This gives y-x=2

Then the number of conditions that meet the conditions is 13 , 24 , 35 , 46 , 57 , 68 , 79

1. Let the two-digit number be ab, then.

10a+b)*9=100a+b

4b=5aa=4 b=5

Yes (11-7) 2=2 2+7=9

3. Set the age of this year ab, there is.

10a+b+18=10b+a

a-b=2 if b=1, a=3

b=2,a=4

1. Let the original two-digit number be AB, which can be expressed as 10A+B; Then add a 0 and a0b in the middle, which can be expressed as 100a+b

There is 100a+b=(10a+b) 9, which can be simplified to obtain: 5a=4b, and a, b can only be a single number, so a=4, b=5, the original number is 45

2. Let the two numbers be a and b respectively, and there is (a + b) (a b) = a b = 77, and it can be found after testing that 9 2 = 77, so the two numbers are 9 and 2 respectively

3. The age of Linli is two-digit AB, so there is BA AB=18, that is, 10B+A (10A+B)=18, which is simplified to: B A=2

So ab can be, are you one less condition?

If you can't assume AB, these questions can be done by turning into vertical fans, and children should be able to understand them. 1、 ab

The last two of a0b can also be turned into vertical reasoning.

The length of the boulevard = (50 40) 20 = 1800 meters The old man has walked 800 meters and then needs to walk 1000 meters to reach the endpoint, then 1000 meters has walked 1000 40 = 25 minutes The old man has walked 1000 meters and needs to walk 800 meters to reach the endpoint

Solution: 54+99 99+45

Solution: (144+96) (44-18).

Solution: [(36-12) 8] 16

Solution 12: 67 9+99 3

Solution: 345 15 + 38 106

Solution: (632 5+632 2+632) 125=632 (5+2+1) 125

Solution: Let's assume that each basket of apples weighs x kilograms.

3x=7(x-20)

4x=140

x=35A: Each basket of apples weighs 35 kilograms.

54+99×99+45=

There does not seem to be the convenience.

It doesn't seem to be any.

It doesn't seem to be.

20 7 3 = 140 3 (kg).

54+99x99+45=99+99x99=99x（1+99）=99x100=9900；

144+96）x（44-18）=240x26=6240；

36-12）x8）/16=（24x8）/16=24/2=12；

67x9+99x3=9x（67+11x3）=9x（67+33）=9x100=900；

345/15+38x106=23+4028+4051；

632x5+632x2+632）x125=632x（5+2+1）x125=632x8x125=632x1000=632000；

Application Problem: Solution: Let each box have y kilograms, then.

7y-20x7=3y

7y-3y=20x7

i.e. 4y = 140

So y=35 (kg).

7×20÷（4/7）=245（kg)

245÷7=35（kg)

Analysis: 7 20 is the weight of the apples taken out, multiply by 4 7 is the total weight of the original apples, and divide by 7 is the weight of a basket of apples.

54+99×99+45

If you take out 20 kg of apples from each basket, the weight of the remaining apples in the 7 baskets is exactly equal to the weight of the original three baskets of apples. How many kilograms did each basket of apples weigh?

Answer: If you take out 20 kg of apples in each basket, the weight of the remaining apples is exactly equal to the weight of the original 3 baskets of apples, so you can know that the weight of the original 4 baskets of apples is exactly what you take out. （20×7）÷（7-3）

35 (kg).

A: Originally, each basket of apples weighed 35 kilograms.

Application:

7*20=140 (kg).

7-3=4 (kg).

140 4 = 35 (kg) (where " " means divided) Answer: Each basket of apples weighs 35 kg.

Solution: Let's assume that each basket of apples weighs x kilograms.

3x=7(x-20)

4x=140

x=35A: Each basket of apples weighs 35 kilograms.