Question

Factorise:4(x2+1)2 +13 (x2+1)-12

Answer 1

4(x²+1)²+13(x²+1)-12
=4(x⁴+2x²+1)+13x²+13-12
=4x⁴+8x²+4+13x²+1
=4x⁴+21x²+5
=4x⁴+20x²+x²+5
=4x²(x²+5)+1(x²+5)
=(x²+5)(4x²+1)

Answer 2

4(x2+1)2 +13 (x2+1)-12

=4(x^4+2x^2+1)+13x^2+13-12

=4x^4+8x^2+4+13x^2+1

=4x^4+21x^2+5

=4x^4+20x^2+x^2+5

=4x^2(x^2+5)+1(x^2+5)

=(x^2+5)(4x^2+1)

****************************************