问几道数学题:1)已知x^2+y^2+6x-4y+13=0,求(x+y)^2008的值.2)已知x+5y=6,求x^2+5xy+3_数学解答

问几道数学题:1)已知x^2+y^2+6x-4y+13=0,求(x+y)^2008的值.2)已知x+5y=6,求x^2+5xy+30y的值

人气：376 ℃　时间：2020-06-23 13:12:02

解答

1.x^2+y^2+6x-4y+13=0
(x+3)^2+(y-2)^2=0
x+3=0,y-2=0
x=-3,y=2
(x+y)^2008=(-1)^2008=-1
2.x^2+5xy+30y
=x(x+5y)+30y
=6x+30y
=6(x+5y)
=6*6
=36