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PLEASE HELPP!!! In the xy -plane, the point (3,6) lies on the graph of the function f(x) = 3x^2 - bx + 12. What is the value of b?

User Bill Doughty
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1 Answer

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15 votes

\begin{gathered} We\text{ have that }f(3)=6 \\ \text{ that means we must solve for b} \\ 3(3^2)-b(3)+12=6 \end{gathered}
\begin{gathered} 3(3^2)-b(3)+12=6 \\ 3\cdot9-3b=6-12 \\ 27-3b=-6 \\ -3b=-6-27 \\ -3b=-33 \\ b=(-33)/(-3) \\ b=11 \end{gathered}

So the value of b is 11

User Chetan Ankola
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