2+3х-(5-2х)=8
2+3х-5+2х=8
5х=8-2+5
5х=11
х=11:5
х=2 1/5
Проверка:
2+3*2 1/5-(5-2*2 1/5)=8
2+33/5-5+22/5=8
2-5+55/5=8
2-5+11=8
8=8
7х-8-(3х+2)=0
7х-8-3х-2=0
4х=8+2
4х=10
х=10/4
х=2 1/2
Проверка:
7*2 1/2-8-(3*2 1/2+2)=0
35/2-8-15/2-2=0
20/2-10=0
10-10=0
0=0