Question

The book is telling me that
-(4x-1)^2+6(4x-1)-11 = -16x^2+32x-18
I keep getting -16x^2+24x-18 I'm I missing something 6(4x) should equal 24x right?

Answer 1

\[(4x-1)^2 = 16x^2 - 8x + 1\]
my full answer:\[-16x^2 + 32x - 18\]

same as textbook lol

Answer 2

\(\bf -(4x-1)^2+6(4x-1)-11\\ \quad \\ \quad \\
\color{blue}{-(4x-1)^2\implies -[(4x)^2-2(4x)(1)+1^2]\implies -16x^2+8x-1}\quad thus\\ \quad \\
-(4x-1)^2+6(4x-1)-11\implies -16x^2+8x-1+24x-6-11\)

Answer 3

Ahh Thank you I forgot how to square such things... thus I could imagine where the extra 8x was coming from!