Question

因式分解化简求值,1.x^4-18x^2y^2+81y^42.m^2-n^2+n-1/4

Answer 1

x^4-18x^2y^2+81y^4

=(x^2-9y^2)^2

=(x+3y)^2(x-3y)^2

m^2-n^2+n-1/4

=m^2-(n^2-n+1/4)

=m^2-(n-1/2)^2

=(m+n-1/2)(m-n+1/2)