8х+12=20
8х=8
х=1
15х-10=5
15х=15
х=1
9х+15=6
9х=6-15
9х=-9
х=-1
8х-6=14
8х=20
х=20/8
х=5/2=2,5
Пошаговое объяснение:
(8х+12) = 20
8x = 20-12
8x = 8
x = 1
(15х-10)=5
15x = 5 + 10
15x = 15
x = 1
(9х +15) =6
9x = 6 - 15
9x = -9
x = -1
(8х - 6)=14
8x = 14 + 6
8x = 20
x = 20:8
x = 2,5
