Answer: C: 12-7x
Step-by-step explanation:
This expression is a good example of the difference of two squares, as 144 is the square of 12, while 49x² is the square of 7x.
Any difference of two squares can be factored into the sum of their square roots times the difference of their square roots
.
Let's factor our expression.
Out of all the options given, only is a factor. Hence, option C is correct.