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43. Which of the following are solutions to the equation -11x = 2x^2 + 15? Select all that apply. A. -5B. -3C. -5/2D. 5/2E. 3F. 5

1 Answer

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We have the next equation


-11x=2x^2+15

First we need o make the equation equal to zero


2x^2+11x+15=0

we have a quadratic equation,we will have 2 solutions, so we will use the general formula to find the solutions to this equation


x_(1,2)=\frac{-b\pm\sqrt[]{b^2-4ac}}{2a}

in our case

a=2

b=11

c=15


x_(1,2)=\frac{-11\pm\sqrt[]{11^2-4(15)(2)}}{2(2)}_{}
x_(1,2)=\frac{-11\pm\sqrt[]{121-120}}{4}=(-11\pm1)/(4)

for the first solution


x=(-11+1)/(4)=-(10)/(4)=-(5)/(2)

for the second solution


x=(-11-1)/(4)=(-12)/(4)=-3

the solutions to the equation given is


x=-(5)/(2),\: x=-3

the correct choices are B. and C.

User FGRibreau
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