Given
[tex]16x^2-56x+49[/tex]We rewrite in the form: a² + 2ab + b²
This is:
[tex]\begin{gathered} 16x^2=(4x)^2 \\ 49=7^2 \\ -56x=-2(4x)(7) \end{gathered}[/tex]Substituting we get:
[tex](4x)^2-2(4x)(7)+7^2[/tex]Apply the square binomial formula:
[tex](4x-7)^2[/tex]Answer:
A is 4
B is 7