Вправи: 4.38

4.38 Перетворіть вираз на дріб:

1) x2- xy+ y2x2- y2 + x2+ xy+ y2(x+y)2 = x2- xy+ y2x-y(x+y) + x2+ xy+ y2(x+y)2 = x+y(x2- xy+ y2)+ x-y(x2+ xy+ y2)(x+y)2(x-y) = x3+ y3+ x3- y3(x+y)2(x-y) = 2x3(x+y)2(x-y);

2) 1(x-2)2 – 2x2- 4 + 1(x+2)2 = (x+2)2- 2x2- 4+ (x-2)2(x-2)2(x+2)2 = x2+ 4x+4-2x2+ 8+ x2- 4x+4(x-2)2(x+2)2 = 16(x2- 4)2.