Решите уравнение 10 * (2- 0.3 х ) + ( 5 - 4 х )= 39
10 * (2- 0.3 х ) + ( 5 - 4 х )= 39 20-3х+5-4х = 39 -7х+25 = 39 -7х = 39-25 -7х = 14 х = -2
...=
20-3х+5-4х=39
-7х=39-25=14
х=-14/7
х=-2