3x-5=4y ②

(1) times 2, and you get

10x+4y=34③

③+②, get

13x=39

x=3

Substitute x=3 into ① to get 15+2y= 17.

y= 1

2.3x-2y=-7①

2x+5y=8②

①x2，get 6x-4y=- 14③。

②x3, you get 6x+ 15y=24④.

④-③. Obtain

19y=38

y=2

Substituting y=2 into ② gives 2x+ 10=8.

2x=-2

x=- 1

3.2y+8=x①

4x+2y= 1 1②

②-①. Obtain

4x-8= 1 1-x

5x= 19

x= 19/5

Substitute x= 19/5 into ① to get

2y+8= 19/5

2y= 19/5-8

2y=-2 1/5

y=-2 1/ 10

4.7x- 13y=25①

9x- 15= 17y②

① Multiply 9 to get 63x- 1 17y=225③.

② Multiply 7 to get 63x-105 =119y④.

④-③. Obtain

- 105+ 1 17y = 1 19y-225

-2y=- 120

y=60

Substitute y=60 into ① to get.

7x-780=25

7x=805

x= 1 15