Question

evaluate (2x+5y)(2x-y)(4x^2+y^2)​

Answer 1

= (2x+5y)(2x-y)(4x^2+y^2)​

= [(2x+5y)(2x-y)](4x^2+y^2)

= (4x^2 - 2xy +10xy - 5y^2)(4x^2+y^2)

= (4x^2 + 8xy - 5y^2)(4x^2+y^2)

= 16x^4 + 32x^3y -20x^2y^2 + 4x^2y^2 + 8xy^3 - 5y^4

= 16x^4 + 32x^3y - 16x^2y^2 + 8xy^3 - 5y^4

=  16x^4 - 5y^4 + 32x^3y + 8xy^3 - 16x^2y^2