Решите плиз 21+75 /2х+13*5=300
(21+75/(2х+13))*5=12021*5 +75*5/(2х+13)=120105 + 375/(2х + 13) = 120375/(2х + 13) = 120 - 105 =152х + 13 =375 : 15 = 252х = 25 - 13 = 122х = 12 х=6