Вправи: 840

840. Спрости вираз:

в) (1x+ xy + 1x- xy) : 2y-1 = 1-y+1+y x(1+ y)(1- y) • y-12 = 2(y-1)1-y•2x = –1x.

г) (aa- b – aa+b) • (b- a)2ab = aa+ b-a( a-b) (a- b)(a+ b) • (b- a)2ab = a+ ab- a+ab a- b • (b- a)2ab = 2ab(a- b)2a- b• ab = 2(a – b).