A few equation questions!!! is in dire needThere is a bonus in 10 minutes!!

Solution:1

Then x=40

Check: substitution, 40*, so left is equal to right.

2.，x=3

Test: Substituting, left equals right, so left equals right.

3., 10x=5, so x=

4.So. So x=

x=60÷

x=40 test, substituting x=40 into the original equation.

The inspection is complete. x=x=3 test, substituting x=3 into the original equation.

The inspection is complete. 3×

10x=10x=5x=5÷10

x=x=x=

1) x=40, substitute x=40 into the original formula, left = 60, right = 602) x = 3, substitute x=3 into the original formula, left =, right = 3) x = 1 2

4)x=

1. (1) Solution: The original plan was to rent x 45-seater cars.

45x+15=60（x-1）

Remove the brackets. Get.

45x+15=60x-60

Move the item, got. 60x-45x=15+60

Simplify, got. 15x=75

coefficient to 1, obtained.

x=5 number of junior high school students: 45x+15=5 45+15=240 (people) (2) Scheme 1 2 3 4 5 6 7

Rental 45-seater passenger car 6 5 4 3 2 1 0Rented 60-seater passenger car 0 1 1 2 3 4 4 Capacity Person 270 285 240 255 270 285 240 Rent Yuan 1320 1400 1180 1260 1340 1420 1200

Option 7, do not rent a 45-seater bus, rent 4 60-seater buses.

2. Solution: Let the speed of B be x meters.

35-5×2）（2x-30）=35x

Go to the brackets and got.

50x-750=35x

Move the item, got. 50x-35x=750

Simplify, got. 15x=750

coefficient to 1, obtained.

x=50A's velocity: 2x-30=2 50-30=70 (mm).

This is the P&L problem

If it is the same car: 15 people in a 45-seater car have no seats, and if you change to a 60-seater bus, there will be one more than 60 seats, a difference of 60+15 75 seats.

The difference between each car is 60-45 and 15 seats.

Got: 75 15 5 (cars).

1.(60+15) (60-45) 5 (vehicles) number: 45 5 15 240 (people).

Car rental: 220*(5+1) 1320 yuan.

60-seater car rental: 300*5 1500 yuan.

It took 10 minutes for A to return 5 minutes later, and 35 minutes later for both of them to arrive at the same time. Dejia took 25 minutes to go from Li Village to Wangzhuang one way.

Method 1: Set B speed to x.

35-5*2)×（2x-30)=35x

x=502x-30=2*50-30=70

Method 2: The speed ratio between A and B is: 1 25 : 1 35 Again: It is known that the distance traveled by A per minute is 30 meters less than twice the distance traveled by B per minute, and the speed of B is x, then the speed of A is 2x-30

1/25 ：1/35=(2x-30)：x

x=502x-30=2*50-30=70

A speed 70, B speed 50

1. This is a typical profit and loss problem.

1) Set the number of people to xYes: (x-15) 45=x 60+1 solution, x=240

Then the original planned number of cars is: (240-15) 45 = 5 (vehicles) (2) is to save money when there are seats.

Set up 45 passenger cars X, 60 passenger cars Y, and meet: 45X+60Y 240, that is, 3X+4Y 16

Take x=4 and y=1 and substitute them for verification.

2. Let the speed of B be x meters per minute, then there is: 35x=(2x-30)*(35-5*2).

Solution: x=50

Then A's velocity is: 70 meters per minute.

If x mothers have lost 2 children, then there are (40-x) mothers who have lost 1 child.

You can list equations:

2x+(40-x)=70

x=30, so there are 30 mothers who have lost two children.

If A has x people, then B has 3 7*x people.

3/7*x+30)/(x-30)=2/3

2(x-30)=3(3/7*x+30)

2x-60=9/7*x+90

2x-9/7*x=90+60

5/7*x=150x=210

A: There were 210 people in A and 90 people in B.

Set A and B to be x kilograms.

x-180)/(2x)=2/5

2*2x=5(x-180)

4x=5x-900

x=900 now.

A has: 900-180 = 720 kg.

B: 900 kg.

300 (people) total number of people.

300 3 10 = 90 (people) Team B.

300 7 10 = 210 (people) Team A.

2. Set X kg for A and B.

x-180)/(2x)=2/5

2*2x=5(x-180)

4x=5x-900

x=900 now.

A has: 900-180 = 720 kg.

B: 900 kg.

1 Solution: If team A has x people, then team B has 3 7x people.

x-30）/（3/7x+30）=3/2

x=210 3/7x=90

A: Team A originally had 210 people, and Team B had 90 people.

2 Solution: If the existing X kg of fruit A, then the existing (x + 180) kg of B fruit.

x=（x+x+180)*2/5

x=360 x+180=540

A: There are 360 kg of fruit A and 540 kg of fruit B.

Set: Family x people then B 7 points 3 people.

Equation 7 points 3x plus 30 is equal to 3 points 2 compared to x minus 30

2 methods almost want to put by oneself.

A car travels at a speed of 40 kilometers per hour from A to B, and after driving for 3 hours, the average speed is forced to decrease by 10 kilometers per hour due to rain, and the result is that it arrives at B 45 minutes later than expected.

Solution: Because of the rain, the average speed was forced to decrease by 10 kilometers per hour, and as a result, it was 45 minutes later than expected.

That is, 45 minutes = 3 4 hours, which is equivalent to 40 3 4 = 30 (kilometers) less

30 10 = 3 (hours) That is, the average speed is forced to decrease by 10 kilometers per hour due to rain, and the time it takes to travel the distance.

Therefore, the distance between A and B is 40 3 + (40-10) 3 = 120 + 90 = 210 (km).

Solve with equations: Solution: Let the estimated time be x. According to the inscription column.

40x=40×3+（40-10）×(x-3+3/4)

40x=120+30x-90+90/4

10x=210/4

x=21/4

That is, the distance between A and B is 40 21 4 = 210 (km).

A: The distance between A and B is 210 km.

The distance between A and B is S km.

s/40 = 3+ (s-40*3)/(40-10)-45/60s/40=3+

s=120+1200s-16000-30

1199s=15910

s=15910/1199

Let the two barrels of brine exchange x kg, because the salt content of the final two barrels of brine is equal, [(60-x)*40%+x*20%] 60=[(40-x)*20%+x*40%] 40

x = 24, i.e. two barrels of brine exchanged for 24 kg.

Solve the exchange of x kilograms.

According to the title, [(60-x)*40%+x*20%] 60=[(40-x)*20%+x*40%] 40

x=24 for 24 kg.