3.7x-3.6x=3.0 1+6.9

0. 1x=9.9 1

x=99. 1

2、0.6(2x- 1.8)=3. 18

2x- 1.8=5.3

2x=5.3+ 1.8

2x=7. 1

x=3.55

3 2.6x-x-0. 1=0.75

1.6x=0. 1+0.75

1.6x=0.85

x=0.53 125

4 x+63.9=9x-2x

7x-x=63.9

6x=63.9

x= 10.65

Solution of column equation

Five times a certain number minus the difference of 10, multiplied by 2, the product is 40. What is a number?

Let this number be x.

2 [5x- 10]=40

5x- 10=20

5x=30

x=6

Solving application problems with train defense process

1. The cross section of the trapezoidal dam is trapezoidal. It is known that the upper bottom is 2,4m and the height is 6m. What is the lower bottom?

Let the bottom be X.

(2.4+x) × 6 ÷ 2 = area subject missing area.

There are 52 monkeys on Monkey Mountain. The number of big monkeys is four times less than that of small monkeys, and there are several big monkeys and small monkeys.

Let the little monkey do X and the big monkey do 4x-8.

x+4x-8=52

5x=60

x= 12

Big monkey =4× 12-8=40.

A: There are 40 big monkeys and 0/2 small monkeys.