(2)5x+3y=3 1

The above two formulas add up.

9x=45

Substitute X=5 into (2)

3y=3 1-25=6

y=2

(1)2x-5y=-2 1 both sides× 2, get (3)

(2)4x+3y=23 (subtract from (3))

(3)4x- 10y=-42

13y=65

Substitute Y=5 (1)

2x=-2 1+25=4

x=2

(1)4x+7y=- 19 (subtract from (2))

(2)4x-5y= 17

12y=-36

Y=-3 is substituted into (2)

4x = 17+5y = 17- 15 = 2

x= 1/2

(1)3(x- 1)= y+5- permutation (3)3x-y=8.

(2)5(y- 1)= 3(x+5)-(4)5y-3x = 20。

(3) and (4) are added.

4y=28

Substitute Y=7 into (3)

3x=8+7= 15

x=5