已知(a+2b)/5=(3b-c)/3=(2c-a)/7,求(c-2b)/(3a+2b)的值假设 (a+2b)/5=(3b-c)/3=(2c-a)/7 = ta = 5t - 2bc = 3b - 3t带入 2c - a = 7t,6b - 6t - 5t +2b = 7t,8b = 18t,b = 9t/4如果 t = 0,b = 0 = a = c,分母 3a+2b ...