3·(x−7) = 0

3x−21 = 0

3x = 21

x = 7

−3·(x+9) = 0

−3x−27 = 0

−3x = 27

x = −9

0,9·(3,2+t) = 0

2,88+0,9t = 0

0,9t = −2,88

t = −3,2

(t−6)·7 = 0

7t−42 = 0

7t = 42

t = 6

15·(6−x) = 0

90−15x = 0

−15x = −90

x = 6

Ответ:

Пошаговое объяснение:

3*(х-7)=0

3х-21=0

3х=21

х=21:3

х=7

-3*(х+9)=0

-3х*(-27)=0

-3х=27

х=27:(-3)

х=-9

0,9*(3,2+t)=0

2,88+0,9t=0

0.9t=-2.88

t=-3.2

(t-6)*7=0

7t-42=0

7t=42

t=42:7

t=6

15*(6-x)=0

90-15х=0

-15х=-90

х=-90:(-15)

х=6