3y+6=8y-9

3y+6=8y-9 3y-8y=-9-6 -5y=-14 y=-14/(-5) y=2,8

3y+6=8y-9 3y-8y=-9-6 -5y=-15 /:(-1) y=3

3y+6=8y-9 3y-8y=-9-6 -5y=-15/:-5 y=3 sprawdzenie: 3y+6=8y-9 3×3+6=8×3-9 15=15