若x^2-y^2=6 x+y=3 则x-y=多少
问题描述:
若x^2-y^2=6 x+y=3 则x-y=多少
答
x^2-y^2=(x+y)(x-y)
6=3(x-y)
x-y=2
若x^2-y^2=6 x+y=3 则x-y=多少
x^2-y^2=(x+y)(x-y)
6=3(x-y)
x-y=2