(21+75/(2х+13))*5=120
Ответы:
(21+75/(2х+13))*5=120
21*5 +75*5/(2х+13)=120
105 + 375/(2х + 13) = 120
375/(2х + 13) = 120 105 =15
2х + 13 =375 : 15 = 25
2х = 25 13 = 12
2х = 12 х=6
(21+75/(2х+13))*5=120
21*5 +75*5/(2х+13)=120
105 + 375/(2х + 13) = 120
375/(2х + 13) = 120 105 =15
2х + 13 =375 : 15 = 25
2х = 25 13 = 12
2х = 12
х=6