РОЗДІЛ 2. Раціональні вирази - Вправи 50 - 200 » 185

185. Знайдіть добуток дробів: 1) (x+1)/3 • 6/〖(x+1)〗^2 = 〖(x+1)•6〗^2/〖3 •(x+1)〗^2 = 2/(x+1); 2) (5y-5)/7 • 21/(y-1) = ((5y-5)•21)/(7 •(y-1)) = (5(y-1)•21)/(7 •(y-1) ) = 15; 3) (2a+1)/8 • 16/(2+4a) = ((2a+1)•16)/(8 •(2+4a)) = ((2a+1)•16)/(8 •2 •(1+2a)) = 1; 4) (1-b)/5 • 20/〖(b-1)〗^2 = ((1-b)•20)/〖5 •(b-1)〗^2 = ((1-b •4)/〖(1-b)〗^2 = 4/(1-b); 5) (3-6y)/14 • 35/(2y-1) = ((3-6y)•35)/(14 •(2y-1)) = (3(1-2y)•35)/(14 •(2y-1)) = –(3(2y-1)•5)/(2(2y-1)) = –15/2 = –7,5; 6) (1-3x)/12 • 16/(6x-2) = ((1-3x)•16)/(12 •(6x-2)) = ((1-3x)•16)/(12 •2(3x-1)) = ((3x-1)•16)/(24 •(3x-1)) = –2/3.