SOLUTION: 16. What are the roots of the equation 3x2 − 9x − 5 = 0? (Points : 5)

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Question 463852: 16. What are the roots of the equation 3x2 − 9x − 5 = 0?
(Points : 5)
Answer by MathLover1(20849)   (Show Source): You can put this solution on YOUR website!
Solved by pluggable solver: Quadratic Formula
Let's use the quadratic formula to solve for x:


Starting with the general quadratic





the general solution using the quadratic equation is:







So lets solve ( notice , , and )





Plug in a=3, b=-9, and c=-5




Negate -9 to get 9




Square -9 to get 81 (note: remember when you square -9, you must square the negative as well. This is because .)




Multiply to get




Combine like terms in the radicand (everything under the square root)




Simplify the square root (note: If you need help with simplifying the square root, check out this solver)




Multiply 2 and 3 to get 6


So now the expression breaks down into two parts


or



Now break up the fraction



or



Simplify



or



So the solutions are:

or




or
or
or
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