2x-6y/x^2-9y^2 已知2x+6y+1=0

问题描述:

2x-6y/x^2-9y^2 已知2x+6y+1=0

8008303380,
2x-6y/x^2-9y^2
=2(x-3y)/(x-3y)(x+3y)
=2/(x+3y)
2x+6y+1=0
2x+6y=-1
x+3y=-1/2
那么2/(x+3y)
=2÷(-1/2)
=-4