Раскройте скобки:

5 - (-х-7,2) = 8,6;

(2 х-5) - (3 х-7) = 4

1.

5 - (-х-7.2) = 8.6

5+х+7.2=8.6

12.2+х=8.6

х=8.6-12.2

х=-3.6

5 - (3.6-7.2) = 8.6

5 - (-3.6) = 8.6

8.6=8.6

2.

(2 х-5) - (3 х-7) = 4

2 х-5-3 х+7=4

-х+2=4

-х=4-2

-х=2

х=-2

(2 * (-2) - 5) - (3 * (-2) - 7) = 4

4=4