Question

Решите уравнение
1) x+28 = 18;
2) -31 – х = -9.​

Answer 1

1) $x+28=18\\x=18-28\\x=-10$

2) $-31-x=-9\\-x=-9+31\\-x=22\\x=-22$

Answer 2

( 1 )

$x+28=18\\\\x=18-28\\\\x=-10$

проверка:

$-10+28=18\\\\28-10=18\\\\18=18$

( 2 )

$-31-x=-9\\\\-x=-9+31\\\\-x=22\\\\x=22:(-1)\\\\x=-22$

проверка:

$-31-(-22)=-9\\\\-31+22=-9\\\\22-31=-9\\\\-9=-9$