-5(0,9x-1,1y)-(1,5х-1,9y)+ (10х-1,4y)= -4,5х + 5,5у - 1,5х + 1,9y + 10х-1,4y = (-4,5х - 1,5х + 10х) + (5,5у + 1,9y - 1,4y) = - 0,5х + 6у
-5(0,9x-1,1y)-(1,5х-1,9y)+ (10х-1,4y)= -4,5х + 5,5у - 1,5х + 1,9y + 10х-1,4y = (-4,5х - 1,5х + 10х) + (5,5у + 1,9y - 1,4y) = - 0,5х + 6у