Math problems must list equations, math problems only list equations...

Solution: The first problem is actually a simple primary function. Set the fee to $y. Scheme A: y=(2+..)i.e. y =

Scenario B: y=

2) This question is to find a tipping point. That's when the two plans cost the same amount of money. So.

So the solution is x=25Then it is divided into three categories. When x is greater than or equal to 0 and less than 25, plan A saves money.

When x=25, ** is the same.

When x is greater than 25, option B saves money. If you still don't understand, don't hesitate to ask me.

Untie; Set the hourly rate to x 1. a..2x+ b..50+ 2.2x+ 2x=50 x=25 equals 25, both are the same Greater than 25, choose the monthly less than 25, choose the plan.

1）a：（

b: 50+2) less than or equal to 62 hours, a is cost-effective.

If it is greater than or equal to 63 hours, B is cost-effective.

Fee) = (2 + yb = 50 +

Discussion:1. When ya-yb >0, that is, 2x-50>0, x>25 ya, the cost of yb is greater than yb, and yb is appropriate.

2。When ya-yb <0, that is, 2x-50<0, the cost of x<25 yb is greater than ya, and it is appropriate.

3。When ya-yb=0, that is, 2x-50=0, x=25, the ya-fee is equal to yb, and both are the same.

The number of cars transporting shiitake mushrooms is x.

The solution is x=4

The number of cars carrying shiitake mushrooms is 4, and the amount of tea is 2.

Set each bought x sheets.

is the total amount of money for the two stamps, and 20-12 is the amount of money used.

The amount of money in a stamp is equal to the money used, and the equation is set according to this principle...

But there's a problem with this problem.,X is not an integer.。。。

1.Solution: There are x stamps for 1 yuan, and (x-5) stamps for 2 yuan.

x+2（x-5）=50

3x =50+10

3x =60

x =60/3

x = 2020-5 = 15 (sheets).

2.Solution: Set up x number of female students and 2x number of male students.

x+8=2/3（2x+8）

x+8=4/3x+16/3

3x+24=4x+16

3x-4x=16-24

x=-8x=8

1 If you buy x stamps with a denomination of one dollar, you will buy (x-5) stamps for two dollars.

x+2（x-5）=50

3x=60x=20

I bought 20 pieces of one dollar face value and 15 pieces of two yuan.

2. Let the original number of girls be x, according to the title.

x+8=（2x+8）*2/3

3x+24=4x+16x=8

Question 1. Let the x sheet of 1 yuan and the y sheet of 2 yuan, and the equation according to the meaning of the question is:

x+2y=50

x-y=5 solves the equation x=20, y=15

Question 2. Let the original number of girls x, then the number of girls in the group is 2xx+8) (2x+8)=2 3

Solution x=8

Question 1. Let the x sheet of one yuan and the y sheet of the two yuan. x+2y=50，x-y=5。The solution is x=20 and y=15.

Question 2. If there are x girls in total, then the boy and the girl are 2x, and after adding eight people, the girl is x+8, and the boy and girl are 2x+8, then the relationship is x+8=2 3 (2x+8). Solution x=8

If a 5-jiao coin is x, then a 1 yuan coin is 20-x

Solution: x = 15 pieces.

There are 15 coins for 5 jiao, and 20-15 = 5 coins for 1 yuan.

There are x pentagonal and Y 1 yuan.

So x+y=20

The solution yields x=15 and y=5

There is 1 piece for 5 corners, and 12 pieces for 1 yuan. I don't know, do I?

Set 5 corners of x, 1 yuan of y, x y 20.

Yuan x 15 pieces, y 5

Solution: Set 1 yuan coin x pieces, 5 jiao coins (20-x) pieces.

1x+x+x=520-5=15 pieces.

Answer: There are 15 pieces of 5 corners and 5 pieces of 1 yuan.

Let it be that A has 7x yuan and B has 6x yuan.

7x-50)/3=(6x-50)/2

2(7x-50)=3(6x-60)

4x=80x=20

Now A = 7 * 20-50 = 90 yuan.

B = 6 * 20-60 = 60 yuan.

B = 6 * 12-

The money on A is x and the money on B is y

x/y=7/6

x-50)/(y-60)=3/2\

The solution is x=140 y=120

Solution: Let A be 7x and B be 6x

7x-50)/(6x-60)=3/2

x=20 A money, 7x=140 yuan.

B money: 6x=120 yuan.

Now A = 7 * 20-50 = 90 yuan.

B = 6 * 20-60 = 60 yuan.

According to the question, set the amount of money on A's body 7x, and B's money on 6x the amount of money after buying something: A (7x-50) (6x-60)= 3 2 Solve the equation: x=20

Initially, A has money 140 and B has money 120, and the rest of the money is A 90 and B 60

Suppose A has $7x on his body and $6 on B.

Then (7x-50) (6x-60)=3 2, solve the equation to get: x=20 so the remaining amount of money: A: 7x-50=90

B: 6x-60=60

Solution: If the amount of money left on the armor is 3x, then the amount of money left on the body is 2x.

3x＋60）∶（2x＋60）＝7∶6

14x＋420＝18x＋360

x 1515 3 45 yuan .........The amount of money left on A's body.

15 2 30 yuan .........The amount of money B has left.

Upstairs is wrong, and the number of sides is n

n-2)180+360 n=1145 solution.

Take a good look at the example problems in the math book.

(30+50)/3*(2+3)=400/3

The distance from Wangjiazhuang to Cuihu is 400 3km away.