Question 888219
Find (f - g)(-5) when f(x) = 5x2 - 7 and g(x) = x + 4


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First compute <font color="blue">f(-5)</font>


f(x) = 5x^2 - 7


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


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


f(-5) = 125 - 7


<font color="blue">f(-5) = 118</font>


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Then find <font color="green">g(-5)</font>


g(x) = x + 4


g(-5) = -5 + 4


<font color="green">g(-5) = -1</font>


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


(f - g)(-5) = <font color="blue">f(-5)</font> - <font color="green">g(-5)</font>


(f - g)(-5) = <font color="blue">118</font> - <font color="green">(-1)</font>


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


(f - g)(-5) = <font color="red">119</font>