若x^2-y^2=30,x+y=6/5,求x-y的值

题目

若x^2-y^2=30,x+y=6/5,求x-y的值
急需急需急需急需急需急需急需急需急需急需急需急需急需急需急需急需急需急需急需急需急需急需急需急需急需急需急需急需急需急需急需急需
我需要过程，擦，明白了么？？？？？？？？？？

答案

x^2-y^2=(x+y)(x-y)=30
x+y=6/5
所以x-y
=(x^2-y^2)/(x+y)
=30÷6/5
=25