Question

[๖²⁴ʱ๖ۣۜLạηɦ ๖ۣۜLùηɠ༉]

 Làm phép nhân:

a)(2+x)(2−x)(4+x2)a)(2+x)(2−x)(4+x²)

b)(x²−2xy+2y²)(x−y)(x+y)

Answer 1

[‿༂ℳïɛ‿༂➴•김태형⁀ᶦᵈᵒᶫ]

Trl:

a) (2+x)(2−x)(4+x2)(2+x)(2−x)(4+x²)

=(4−2x+2x−x²)(4+x²)

=(4−x²)(4+x²)

=16+4x²−4x²−x⁶=16−x⁴

b) (x²−2xy+2y²)(x−y)(x+y)

=(x²−2xy+2y²)(x²+xy−xy−y²)

=(x²−2xy+2y²)(x²−y²)

=x⁴−x²y²−2x³y+2xy³+2x²y²−2y⁴

=x⁴+x²y²−2x³y+2xy³-2xy⁴