已知x²-4x+y²-10y+29=0,求x²y²+2x³y³+x^4•y²的值
问题描述:
已知x²-4x+y²-10y+29=0,求x²y²+2x³y³+x^4•y²的值
答
x²-4x+y²-10y+29=0可分解为:(x-2)^2+(y-5)^2=0
x=2 y=5
代入:x²y²+2x³y³+x^4•y²
可得:4x25+16x125+16x25
=2100+400
=2500
答
解
x²-4x+y²-10y+29=0
(x²-4x+4)+(y²-10y+25)=0
(x-2)²+(y-5)²=0
∴x-2=0,y-5=0
∴x=2,y=5
∴x²y²+2x³y³+x^4y²
=4×25+2×8×125+16×25
=100+2000+400
=2500
答
x²-4x+4+y²-10y+25=0(x-2)²+(y-5)²=0x-2=0y-5=0∴x=2y=5x²y²+2x³y³+x^4•y²=x²y²(1+2xy+x²)=100(1+20+4)=2500