GCF=4
4(4x^2/4+-28x/4+-32f/4)
=4(x^2-7x-8f)
Hello,
[tex]4x^2-28x-32\\\\=4(x^2-7x-8)\\\\=4(x^2-8x+x-8)\\\\=4[x(x-8)+1(x-8)]\\\\=4(x-8)(x+1)\\[/tex]
