Вправи 201 - 300 » 217 (1-5)

216. Знайдіть частку дробів: 1) (y+ 3)/4 : (y+3)/36 = (y+3)/4 • 36/(y+3) = ((y+3)•36)/(4 •(y+3)) = 9; 2) (3x+1)/15 : (3+9x)/35 = (3x+1)/15 • 35/(3+9x) = ((3x+1)•35)/(15 •(3+9x)) = ((3x+1)•7)/(3 •3(1+3x)) = ((3x+1)•7)/(9 •(3x+1)) = 7/9; 3) (2-5y)/10 : (15y-6)/50 = (2-5y)/10 • 50/(15y-6) = ((2-5y)•50)/(10 •(15y-6)) = ((2-5y)•5)/(3 •(5y-2)) = –((5y-2)•5)/(3 •(5y-2)) = –5/3 = –12/3.