- 5 + 2t = - 7
2t = - 7 + 5
2t = - 2
t = - 2 : 2
t = -1
------------------------
- 5 + 2 * (- 1) = - 7
- 5 + (- 2 ) = - 7
- 7 = - 7
5х = - 8 + х
5х - х = - 8
4х = - 8
х = - 8 : 4
х = - 2
---------------------
5 * (- 2) = - 8 + (- 2)
- 10 = - 10
- 4у = 7 + 3у
- 4у - 3у = 7
- 7у = 7
у = 7 : (- 7)
у = - 1
--------------------------------
- 4 * (- 1) = 7 + 3 * (- 1)
4 = 7 - 3
4 = 4
8m = - 2m + 9
8m + 2m = 9
10m = 9
m = 9/10
-------------------------------
8 * 9/10 = - 2 * 9/10 + 9
7 1/5 = - 1 4/5 + 9
7 1/5 = 7 1/5