Question

Find f(5)+j(-2) if f(x)=12-3x and j(x)=x² + 4x - 1.

Answer 1

-8

Explanation:

Put the given values where the corresponding variables are, and do the arithmetic.

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first function

f(x) = 12 -3x

f(5) = 12 -3(5) = -3

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second function

j(x) = x² +4x -1 = (x +4)x -1

j(-2) = (-2 +4)(-2) -1 = 2(-2) -1 = -5

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composition

f(5) +j(-2) = -3 +(-5) = -8