SOLUTION: Find (f - g)(-5) when f(x) = 5x2 - 7 and g(x) = x + 4

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Question 888219: Find (f - g)(-5) when f(x) = 5x2 - 7 and g(x) = x + 4
Answer by jim_thompson5910(35256) About Me  (Show Source):
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Find (f - g)(-5) when f(x) = 5x2 - 7 and g(x) = x + 4

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First compute f(-5)

f(x) = 5x^2 - 7

f(-5) = 5(-5)^2 - 7

f(-5) = 5(25) - 7

f(-5) = 125 - 7

f(-5) = 118

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Then find g(-5)

g(x) = x + 4

g(-5) = -5 + 4

g(-5) = -1

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Use them both to find (f - g)(-5)

(f - g)(-5) = f(-5) - g(-5)

(f - g)(-5) = 118 - (-1)

(f - g)(-5) = 118 + 1

(f - g)(-5) = 119