Adding and subtracting rational expressions.

Question

3x/x^2+x-12 - x/x^2-16

Answer 1

Online you needed parentheses so things are not ambiguous. You want a common denominator, so note that

x^2+x-12 = (x+4)(x-3)
x^2-16 = (x+4)(x-4)

Now you can see that the LCD is

(x+4)(x-4)(x-3)

and work with that.

Answer 2

i would have never figured this out