College algebra word problem

Question

Given R(x), find R(−2).

R(x) 3x+16/-6x^3+38x

Answer 1

just replace x by -2 to get

3(-2)+16/-6(-2)^3+38(-2) = -6+16/-8-76 = 10/-76 = -5/38

that's true, if you had implicit parentheses as in (3x+16)/(-6x^3+38x)

but if you didn't intend that, then the answer would be different

3(-2) + 16/-(-2)^3 + 38(-2) = -6 +16/-8 -76 = -6 -16/8 - 76 = -6 -2 - 76 = -84

It makes a huge difference depending on where you intended the parentheses to be

-84 would be the correct answer given the usual order of operations PEMDAS, in order, parentheses, exponents, multiplication, division, add, subtract. without parentheses, the answer is -84