1) 15x-3=10x+12 2) - 2x-25=-5x-7 3) 4 (5-2y) = 2 (1-y) 4) 3y+16=8y-9 5) 4x + (11,8-x) = 3,8-5x

1) 15x-3=10x+12

15x-10x=3+12

5x=15

x=15/5

x=3

2) - 2x-25=-5x-7

-2x+5x=25-7

3x=18

x=18/3

x=6

3) 4 (5-2y) = 2 (1-y)

4*5-4*2y=2*1-2*y

20-8y=2-2y

-8y+2y=2-20

-6y=2-20

-6y=-18

6y=18

y=18/6

y=3

4) 3y+16=8y-9

3y-8y=-9-16

-5y=-25

5y=25

y=25/5

y=5

5) 4x + (11,8-x) = 3,8-5x

4x+11,8-x=3,8-5x

4x-x+5x=3,8-11,8

3x+5x=-8

8x=-8

x=-8/8

x=-1