Вправи 201 - 300 » 215

215. Знайдіть частку дробів: 1) (x+1)/3 : (x+1)/15 = (x+1)/3 • 15/(x+1) = ((x+1)•15)/(3 •(x+1)) = 5; 2) (5y-5)/7 : (y-1)/28 = (5y-5)/7 • 28/(y-1) = ((5y-5)•28)/(7 •(y-1)) = (5(y-1)•28)/(7 •(y-1)) = 20; 3) (2a+1)/8 : (4a+2)/16 = (2a+1)/8 • 16/(4a+2) = ((2a+1)•16)/(8 •(4a+2)) = ((2a+1)•2)/(2(2a+1)) = 1; 4) (1-b)/5 : 〖(b-1)〗^2/25 = (1-b)/5 • 25/〖(b-1)〗^2 = ((1-b)•25)/(5(b-1)^2 ) = ((1-b)•5)/〖(1-b)〗^2 = 5/(1-b); 5) (3-6y)/14 : (2y-1)/42 = (3-6y)/14 • 42/(2y-1) = ((3-6y)•42)/(14 •(2y-1)) = (3(1-2y)•42)/(14 •(2y-1)) = –9; 6) (1-3x)/18 : (9x-3)/42 = (1-3x)/18 • 42/(9x-3) = ((1-3x)•42)/(18 •(9x-3)) = –((3x-1)•7)/(9 •(3x-1)) = –7/9;