Выполните действие с дробями 1) 7/9 × 7/16=? 2) 13/10×25/39=? 3) 4/9÷32/63=? 4) 8/35÷3/7=?

1) 7/9 * 7/16 = (7 * 7)/(9 * 16) = 49/144 2) 13/10 * 25/39 = (13 * 25)/(10 * 39) = (13 * 25 : 5)/(10 : 5 * 39) = (13 * 5)/(2 * 39) = (13 : 13 * 5)/(2 * 39 : 13) = (1 * 5)/(2 * 3) = 5/63) 4/9 : 32/63 = 4/9 * 63/32 = (4 * 63)/(9 * 32) = (4 : 4 * 63)/(9 * 32 : 4) = (1 * 63)/(9 * 8) = (1 * 63 : 9)/(9 : 9 * 8) = (1 * 7)/(1 * 8) = 7/84) 8/35 : 3/7 = 8/35 * 7/3 = (8 * 7)/(35 * 3) = (8 * 7 : 7)/(35 : 7 * 3) = (8 * 1)/(5 * 3) = 8/15