Question

已知:(x+2)2+|y+1|=0,求5xy2-{2x2y-[3xy2-(4xy2-2x2y)]}的值

Answer 1

(x+2)2+|y+1|=0,
则x+2=0，y+1=0
则x=-2，y=-1
5xy2-{2x2y-[3xy2-(4xy2-2x2y)]}
=5xy²-2x²y+3xy²-4xy²+2x²y
=4xy²
=4×(-2)×(-1)²
=-8

Answer 2

因为|y+1|>=0，(x+2)2>=0
为保证两者之和等于0，所以
只能是|y+1|=0，(x+2)2=0
所以y=-1,x=-2
代入式中，得
-8

Answer 3

(x+2)2+|y+1|=0,
则x+2=0，y+1=0
则x=-2，y=-1
5xy2-{2x2y-[3xy2-(4xy2-2x2y)]}
=5xy²-2x²y+3xy²-4xy²+2x²y
=4xy²-4x²y
=4×(-2)×(-1)²-4×（-2）²×（-1）
=8

Answer 4

x+2=0 x=-2
y+1=0 y=-1
5xy²-{2x²y-[3xy²-[4xy²-2x²y]]]
=4xy²=-8

Answer 5

x+2=0且y+1=0所以x=-2 y=-1 后面的那个化简的4xy2 带入x y 结果-8

Answer 6

-8