已知I3x+2y+3I+(5y+2x-9)^2=0,求x^2+y^2的值._数学解答

已知I3x+2y+3I+(5y+2x-9)^2=0,求x^2+y^2的值.

人气：176 ℃　时间：2020-06-23 15:59:04

解答

I3x+2y+3I+(5y+2x-9)^2=0
I3x+2y+3I=0
3x+2y+3=0
3x+2y=-3.1
(5y+2x-9)^2=0
5y+2x-9=0
2x+5y=9.2
1式*2-2式*3得
-11y=-33
y=3
x=-3
x^2+y^2
=(-3)^2+3^2
=9+9
=18