Question

x-y+4xy/x-y 4xy/x-y是一个整体 1-x+x平方/x+1 x平方/x+1是一个整体 x-1/x+1+4x

Answer 1

x-y+4xy/x-y

=[(x-y)^2+4xy]/(x-y)

=(x+y)^2/(x-y)

1-x+x平方/x+1

=[(1-x)(1+x)+x^2]/(x+1)

=1/(x+1)

x-1/x+1+4x/x平方-1

=[(x-1)(x-1)+4x]/(x^2-1)

=(x+1)^2/(x^2-1)

=(x+1)/(x-1)

4/x平方-4+2/x+2-1/x-2

=[4+2(x-2)-(x+2)]/(x^2-4)

=(x-2)/(x^2-4)

=1/(x+2)

你能明白,赞同