Question

初一计算题2道[(m+n)平方-4(m-n)平方]÷(3n-m)=[(a-2b)平方-4(a-2b)+4]÷(a-2b-

Answer 1

[(m+n)^2-4(m-n)^2]/(3n-m)

=[(m+n)+2(m-n)][(m+n)-2(m-n)]/(3n-m)

=[3m-n][3n-m]/(3n-m)

=3m-n

[(a-2b)^2-4(a-2b)+4]/(a-2b-2)

=[(a-2b)-2]^2/(a-2b-2)

=a-2b-2