Use the equation of first degree with one variable to solve, otherwise it will not be calculated Xiao Ming went to his father's supermarket to participate in social practice activities. One day, Xiao Ming and his father exchanged 58 pieces of change from the bank, totaling 200 yuan, for customers' change when they paid. After careful cleaning up, Xiao Ming found that there were 20 pieces with a face value of 1 yuan and 7 pieces with a face value of 10 yuan, The rest are 2 yuan and 5 yuan bills. Can you use the math method you have learned to calculate the number of 2 yuan and 5 yuan bills? Please write down the calculation process

Use the equation of first degree with one variable to solve, otherwise it will not be calculated Xiao Ming went to his father's supermarket to participate in social practice activities. One day, Xiao Ming and his father exchanged 58 pieces of change from the bank, totaling 200 yuan, for customers' change when they paid. After careful cleaning up, Xiao Ming found that there were 20 pieces with a face value of 1 yuan and 7 pieces with a face value of 10 yuan, The rest are 2 yuan and 5 yuan bills. Can you use the math method you have learned to calculate the number of 2 yuan and 5 yuan bills? Please write down the calculation process

Suppose there are x 2 yuan notes, then there are 58-20-7-x = 31-x 5 yuan notes
According to the meaning of the title, 2x + 5 (31-x) = 200-20-70 = 110
The solution is x = 15, so 31-x = 16
There are 15 two dollar bills and 16 five dollar bills

Find 250 primary school mathematics fifth grade solution equation (urgent!)
It's not an applied problem,

3.5x = 140 2x +5 = 40 15x+6x = 1685x＋1.5 = 4.5 13.7—x = 5.29 4.2 × 3—3x = 5.1 35-X=4(X+5) (0.5+x)+x=9.8÷2 2(X+X+0.5)=9.8 25000+x=6x 3200=450+5X+X X-0.8X=612x-8x=4.8 7.5*2X=15 1.2x=81.6 52－x ＝15...

1.3/x=1.5
3 / X * 3 = 1.5 * 3 (3 left on both sides)
X = 4.5 (the correct answer is x = 2)
3 divided by X, I have 3 left on both sides, and it becomes x = 1.5 * 3. Why is it wrong?
Why is 3 / 3 / x = 3 / 1.5? I really can't understand it
Why does 3 appear before 1.5 and divide by 1.5
The following are the same questions. There is only one example in the book that doesn't have this type
2.(36-4a)/8=1
(36-4a)/8*8=1*8
36-4a=8
36-4a+36=8+36
4a=44
4a/4=44/4
A = 11 (the correct answer is 7)
Why 36-4a = 8 should be written as 36-36-4a = 36-8? Why 36 can be written in front? Why 36 should be - 36 instead of + 36? There is no similar problem in the book. I haven't seen other people solve it. The above is my own thought. Only in this way can the answer be the same as the correct answer. Why should I do this? I'm afraid I can't understand it. I'm not a primary school student for hundreds of years Use () to write out every step of thinking, just like the title in the book

Multiply both sides by X. multiply the denominator at the same time to simplify. In the second part, add 4a to both sides

Xiao Ming bought two identical fans and a bicycle in the shopping mall. The price of a bicycle is 40 yuan more than six times that of an electric fan. Three items cost 720 yuan in total. How much is an electric fan? (lie equation)

Let x yuan be a fan. 2x + (6x + 40) = 720, 8x + 40 = 720, 8x = 680, x = 85 a fan is 85 yuan

Primary school equation checking. Today I show my children homework. I can't make up my mind how to check. I didn't have to work hard in school before, but now I can't do math in primary school. I'm really ashamed!
8 + 5x = 38 checking calculation:
5x=38-8
5x=30
x=6
5 * 8x-37 = 23 checking calculation:
8x=(23+37)/5
8x=60/5
8x=12
x=1.5
2x-7.2 = 6.4 checking calculation:
2x=6.4+7.2
2x=13.6
x=13.6/2
x=6.8

8 + 5x = 38 checking calculation: when x = 6, 8 + 5 * 6 = 385x = 38-85x = 30, x = 65 * 8x-37 = 23 checking calculation: when x = 1.5, 5 * 8 * 1.5-37 = 238x = (23 + 37) / 58x = 60 / 58x = 12x = 1.5

（12-x）/18=(17-x)/20

（12-x）/18=(17-x)/20
（12-x）*20=(17-x)*18
240-20x=306-18x
240-306=20x-18x
-66=2x
x=-33

6.2x + 2x = 12.3 [2] 5.1x-4x = 45.1 [3] x-0.45 = 11

　　6.2x+2X=12.3 5.1X-4X=45.1 X-0.45=11
　　8.2x=12.3 1.1x=45.1 x=11+0.45
x=1.5 x=41 x=11.45
Please accept, thank you!

X-0.36x = 64 solved by equation

x-0.36x=64
0.64x=64
x=100

How to write the checking process of solving equation x + 7 = 7 in grade 4 of primary school

Inspection:
Take x into the original equation
Equation left = x + 7 = 0 + 7 = 7
Equation right = 7
Because the left is equal to the right
So x = 0 is the solution of the original equation

Solving equation and checking calculation
x÷1.2=0.08 2x-3.05=6.5 4（x+2.5）÷3=24

x÷1.2=0.08
x÷1.2*1.2=0.08*1.2
X=0.096
Checking calculation: bring x = 0.096 into the original equation
Left = 0.096 △ 1.2
=0.08
=Right
So, x = 0.096 is the solution of the original equation
2x-3.05=6.5
2x-3.05+3.05=6.5 +3.05
2 X=9.55
x=4.775
Checking calculation: bring x = 4.775 into the original equation
Left = 2 * 4.775-3.05
=9.55-3.05
=6.5
=Right
So, x = 4.775 is the solution of the original equation
4（x+2.5）÷3=24
4（x+2.5）÷3*3=24*3
4（x+2.5）=72
x+2.5 =72÷4
x+2.5 =18
x+2.5 -2.5=18-2.5
x=15.5
Checking calculation: bring x = 15.5 into the original equation
Left = 4 (15.5 + 2.5) △ 3
=4*18÷3
=72÷3
=24
=Right
Therefore, x = 15.5 is the solution of the original equation