当|x+5|+(y-2)方=0时,求(4x-2y方)-[5x-(x-y)方]-x的值
问题描述:
当|x+5|+(y-2)方=0时,求(4x-2y方)-[5x-(x-y)方]-x的值
答
由已知等式,x=-5,y=2
∴(4x-2y²)-[5x-(x-y)²]-x=(-20-8)-[-25-49]+5=51
答
由|x+5|+(y-2)方=0,所以可求得x=5 y=-2 代入后面的算式可求得最后结果的值
答
x+5=0 x=-5
y-2=0 y=2
(4x-2y^2)-[5x-(x-y)^2]-x
=[4×(-5)-2×2^2]-[5×(-5)-(-5-2)^2]-(-5)
=(-20-8)-(-25-49)+5
=51