Вправи: 305

305. Виконай дії.

а) х+2х+3 : 5х+109-х2 – 2х-115 = х+2•(9-х2)х+3•5(х+2) – 2х-115 = (3-х)5 – 2х-115 = 9-3х-2х+115 = 10-5х15 = 5(2-х)15 = 2-х3;

б) (6yy-4 – 3y) : 6-yy-4 = 6y- 3y2+ 12yy-4 • y-46-y = 18y-3y26-y = 3y(6-y)6-y = 3y;

в) x2- y2(x-y)2 • x2x+y + 1-x2x-y = x+yx-y • x2x-y + 1-x2x-y = x2x-y + 1-x2x-y = x2+ 1- x2x-y = 1x-y;

г) 5-m5+m • (m + 2m25-m) = 5-m5+m • (5m- m2+ 2m25-m) = 5-m• (5m+m2)5+m•(5-m) = m(5+m)m+5 = m.