Вправи: 824

824. Спростіть вираз:

1) 7yy2- 4 – 14y2- 4 = 7y-14y2- 4 = 7(y-2)y-2(y+2) = 7y+2;

2) y2- 3y25- y2 – 7y-2525- y2 = y2- 3y- (7y-25)25- y2 = y2- 3y-7y+2525- y2 = y2- 10y+2525- y2 = (y-5)25-y(5+y) = 5-y5+y;

3) 9p+ 53p+6 – 10p-123p+6 + 9p-13p+6 = 9p+5- 10p-12+ (9p-1)3p+6 = 9p+5-10p+12+9p-13p+6 = 8p+163p+6 = 8(p+2)3(p+2) = 83;

4) 7x+53-x + 5x+11x-3 = 7x+53-x – 5x+113-x = 7x+5- (5x+11)3-x = 7x+5-5x-113-x = 2x-63-x = -2(3-x)3-x = –2;

5) (3a-1)24a-4 + (a-3)24-4a = (3a-1)24a-4 – (a-3)24a-4 = (3a-1)2- (a-3)24a-4 = 3a-1-a+3(3a-1+a-3)4(a-1) = 2a+2(4a-4)4a-4 = 2a + 2;

6) x2- 3x(2-x)2 – x-4(x-2)2 = x2- 3x- (x-4)(x-2)2 = x2- 3x-x+4(x-2)2 = x2- 4x+4(x-2)2 = (x-2)2(x-2)2 = 1;

7) 7a-2 – b2-a = 7a-2 + ba-2 = b+7a-2;

8) 6a5-a – 4aa-5 = 6a5-a + 4a5-a = 10a5-a.