Вправи: 158

158. Спростіть вираз:

1) x-13 + x-23 + x-33 = x-1+x-2+x-33 = 3x-63 = 3(x-2)3 = x – 2;

2) 2a2- 3b25ab – 2b2- 3a25ab = 2a2- 3b2- 2b2+ 3a25ab = 5a2- 5b25ab = 5(a2- b2)5ab = a2- b25ab;

3) x-y2x-3y – 2y-x2x-3y = x-y-2y+x2x-3y = 2x-3y2x-3y = 1

4) 2x2- 3y23xy – 3y2- x23xy = 2x2- 3y2- 3y2+ x23xy = 3x2- 6y23xy = 3(x2- 2y2)3xy = x2- 2y2xy.