Question

How do you factor `144-x^2`?

Answer 1

`(12+x)(12-x)`

Explanation:

I can "see" in this expression this general one:
`(a+b)(a-b)=a^2-b^2`
where:
`a^2=144` so that `a=12`
`b^2=x^2` so that `b=x`
Using these options I get:
`(12+x)(12-x)=(12*12)cancel(-(12*x))cancel(+(12*x))-(x*x)=`
`=144-x^2`