Вправи: 155

155. Спростіть вираз:

1) 2\x-33+x – 2xx2- 9 = 2x-6-2xx2- 9 = –6x2- 9;

2) 4xx2- 25 – 4x-5 = 4xx-5(x+5) – 4\x+5x-5 = 4x-4x-20x-5(x+5) = –20x2- 25;

3) 26+c + 2c36-c2 = 2\6-c6+c + 2c6-c(6+c) = 12-2c+2c6-c(6+c) = 1236-c2;

4) 5x+7 – 10xx2- 49 = 5\x-7x+7 – 10xx-7(x+7) = 5x-35-10xx-7(x+7) = –-5x-35x2- 49;

5) 2y+1 – 1+2yy2- 1 = 2\y-1y+1 – 1+2yy-1(y+1) = 2y-2-1-2yy-1(y+1) = –3y-1(y+1);

6) 4c2- 4 – 4-cc-2 = 4c-2(c+2) – 4-c\c+2c-2 = 4-(4c+8-c2- 2c)c-2(c+2) = 4-4c-8+ c2+ 2cc2- 4 = c2- 2c-4c2- 4.