Вправи: 208

208. Виконайте дії:

1) (11-a2 – 1a2+ 2a+1) : 2aa2- 1 = (1(1- a)(1+ a) – 1(a+1)2) • a2- 12a = a+1-(1- a)(1- a)(1+ a)2 • (a-1)(a+1)2a = 2a(a-1)(a+1)-(a-1)(a+1)2 • 2a = –1a+1.

2) (x+12x-2 – x+32x+3 + 62x2-2) • 4x2-45 = (x+1)2-x+3x-1+62(x-1)(x+1) • 4x2-45 = (x2 +2x+1- x2-3x+ x+3+6)2x2 -1 • 5 = 10 • 42 • 5 = 4.