Вправи: 185

185. Знайдіть добуток дробів:

1) x+13 • 6(x+1)2 = x+1•623 •(x+1)2 = 2x+1;

2) 5y-57 • 21y-1 = 5y-5•217 •(y-1) = 5y-1•217 •y-1 = 15;

3) 2a+18 • 162+4a = 2a+1•168 •(2+4a) = 2a+1•168 •2 •(1+2a) = 1;

4) 1-b5 • 20(b-1)2 = 1-b•205 •(b-1)2 = (1-b •4(1-b)2 = 41-b;

5) 3-6y14 • 352y-1 = 3-6y•3514 •(2y-1) = 31-2y•3514 •(2y-1) = –32y-1•52(2y-1) = –152 = –7,5;

6) 1-3x12 • 166x-2 = 1-3x•1612 •(6x-2) = 1-3x•1612 •2(3x-1) = 3x-1•1624 •(3x-1) = –23.