### Instruction: Factor $36-9x^2$.### Response: Ok, so we have $36-9x^2$.
We can factor out a 9 from this expression, so we get $9(4-x^2)$.
But wait! We can factor the expression in the parentheses even further.
That's right. $4-x^2$ is a difference of squares, so we can factor it into $(2+x)(2-x)$.