Question

若（2x-y）的平方+|y+2丨=o，求代数式[(x-y)的平方+(x+y)(x-y)除以2x的值

Answer 1

（2x-y）的平方+|y+2丨=o
2x-y=0 y+2=0
x=-1 y=-2
代数式[(x-y)的平方+(x+y)(x-y)除以2x
=[(x-y)^2+(x+y)(x-y)]/2x
=(x-y)(x-y+x+y)/2x
=(x-y)*2x/2x
=x-y
=-1-(-2)
=1

Answer 2

（2x-y）的平方+|y+2丨=o
则2x-y=0，y+2=0
则2x=y，y=-2
则x=-1，y=-2
[(x-y)的平方+(x+y)(x-y)]除以2x
=(x-y)(x-y+x+y)÷2x
=(x-y)×2x÷2x
=x-y
=-1-(-2)
=1