Question

一道初三数学题!急!已知2分之a等于3分之a,5分之b等于4分之c,求b减c分之a加b的值.鄙人不才,望高人指点.

Answer 1

∵a/2 = b/3 ∴ a/b = 2/3

∵ b/5 = c/4 ∴ c/b =4/5

(a+b) / (b-c) = (a/b +1) / (1- c/b) 【分子分母同除以b】

= (2/3 +1) / (1- 4/5) = 25/3