Question

let f(x)=x^2-13 and g(x)=16-x. Perform the composition or operation indicated.
(f\g)(-9)

Answer 1

Did you ask what will be the value if I plugin -9 into (x^2-13)/(16-x)?

In that case the answer will be 2.72.
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Try this: let, h(x)=(16-x)^2-13. Now find h(-9). [note that (a-b)^2=a^2-2ab+b^2]

Answer 2

(f/g)(x) = f(x)/g(x)
(f/g)(-9) = (-9)^2 - 13/(16+9)
(f/g)(-9) = 81 - 13/25
(f/g)(-3) = 68/25