Question 325567
This is a difference of two squares which factors like this,
{{{Z^2-A^2=(Z+A)(Z-A)}}}
In this case,
{{{Z^2=4x^2}}}
{{{Z=2x}}}
.
.
.
{{{A^2=49}}}
{{{A=7}}}
So then,
{{{4x^2-49=(2x-7)(2x+7)}}}