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F (x) = 10 – 3x – 22*This can be factored using the quadratic formula

F (x) = 10 – 3x – 22*This can be factored using the quadratic formula-example-1
User Soorajlal K G
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1 Answer

9 votes
9 votes

You have to factor the following function


f(x)=10-3x-x^2

The coefficients of the function are:

a=-1

b=-3

c=10

Using the quadratic formula you have to calculate the roots of the function


x=\frac{-b\pm\sqrt[]{b^2-4ac}}{2a}

Replace the formula with the values of the coefficients of the function


\begin{gathered} x=\frac{-(-3)\pm\sqrt[]{(-3)^2-4(-1)10}}{2(-1)} \\ x=\frac{3\pm\sqrt[]{9+40}}{-2} \\ x=\frac{3\pm\sqrt[]{49}}{-2} \\ x=(3\pm7)/(-2) \end{gathered}

Positive calculation:


\begin{gathered} x=(3+7)/(-2) \\ x=(-10)/(-2) \\ x=-5 \end{gathered}

Negative calculation


\begin{gathered} x=(3-7)/(-2) \\ x=(-4)/(-2) \\ x=2 \end{gathered}

The roots of the function are x=-5 and x=2

The factorized function is


f(x)=(x+5)(x-2)

Note that the roots have to have the inverse sign when you write the factorized function.

The final step is to multiply the function by -1, to make it point downwards just like the original one.


f(x)=-(x+5)(x-2)

User Spikyjt
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