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Let f(x) = 5x^2 - 2x -9calculate f(-4) - f(-2)

User Richardo
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1 Answer

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We are required to evaluate the given function at x=-4 and at x=-2.

Let's start by evaluating the function when x=-4:


\begin{gathered} f(x)=5x^2-2x-9 \\ f(-4)=5(-4)^2-2(-4)-9 \\ f(-4)=5*16+8-9 \\ f(-4)=79 \end{gathered}

Now, we evaluate the function at x= -2:


\begin{gathered} f(x)=5x^2-2x-9 \\ f(-2)=5(-2)^2-2(-2)-9 \\ f(-2)=5*4+4-9 \\ f(-2)=15 \end{gathered}

Finally, we have to compute f(-4) - f(-2), which is:


f(-4)-f(-2)=79-15=64

Hence the answer is 64.

User Michael Millar
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