(a/a的二次方-b的二次方)-(1/a+b)÷b/b-a 化简或计算

题目

(a/a的二次方-b的二次方)-(1/a+b)÷b/b-a 化简或计算

答案

[a/(a² - b²) - 1/(a + b)] ÷ b/(b - a)
= [a/(a² - b²) -(a - b)/(a² - b²) ] × (b - a)/b
= b/(a² - b²) × (b - a)/b
= -1/(a + b)