Question

Tìm số nguyên x ,biết :

a) 7 - x = 8 - (- 7).

Answer 1

\(7-x=8-\left(-7\right)\)

\(7-x=8+7\)

\(7-x=15\)

\(x=7-15\)

\(x=-8\)

Answer 2

7-x = 8- (-7)

=7- x= 8+7

=> 7-x=15

=> x=7-15

=>x=-8