. 5(2x + 4) – 3(5x – 1) = 12;
5(2х+4)-3(5х-1)=12 10х+20-15х+3=12 10х-15х=12-3-20 -5х=-11 х=-11:(-5) х=2,2
5(2x + 4) - 3(5x - 1) = 12 10x + 20 - 15x + 3 = 12 -5x + 23 = 12 -5x = -11 5x = 11 x= 11/5 = 2,2 Ответ: 2,2