Question

Решите уравнения
89 + (17 - x)=81
х -13 = 513
157 - (х + 7)=130

Answer 1

$89 +(17 - x) = 81 \\ 89 + 17 - x = 81 \\ - x = 81 - 89 - 17 \\ - x = - 25 \\ x = 25$
Ответ: х = 25
$x - 13 = 513 \\ x = 513 + 13 \\ x = 526$
Ответ: х = 526
$157 - (x + 7) = 130 \\ 157 - x - 7 = 130 \\ - x = 130 - 157 + 7 \\ - x = - 20 \\ x = 20$
Ответ: х = 20

Answer 2

1) 89+(17-х)=81
89+17-x=81
89+17=106
106-x=81
-x=106-81
-x=-25
x=25
2) х -13=513
х=513+13
х=526
__________
526-13=513
513=513

3) 157-(х+7)=130
х=157-(130+7)
х=20
_____________
157-(20+7)=130
130=130