两个分数之和等于1又125/147,它们分子之比是5：11,而分母之比是3：7,这两个分数是（）、（）求大神帮

题目

两个分数之和等于1又125/147,它们分子之比是5：11,而分母之比是3：7,这两个分数是（）、（）求大神帮

答案

a/b + x/y = 1 + 125 / 147 = 272 / 147 a :x = 5 :11 ==> x = 11a/5 b :y = 3 :7 ==> y = 7b /3 ==> a/b + (11a/5) / (7b/3) = 272/147 ==> a/b + a/b * (11/5 * 3/7) = 272/147 ==> a/b + a/b * 33/35 = 272 / 1 47 ==> a/b * (1 + 33/35) = 272 / 147 ==> a/b * (68/35) = 272 / 147 ==> a/b = 272/147 * 35 / 68 ==> a/b = (272*35) / (147*68) ==> a/b = 20/21 x/y = (1 + 125/147) - 20 / 21 = 1/21 + 125/147 = 132/147 = 44/49 这两个分数是（20/21）、（44/49）.