SOLUTION: can you solve using the quadratic formula x^2+6x-8=0

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Question 143165: can you solve using the quadratic formula
x^2+6x-8=0
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Let's use the quadratic formula to solve for x:


Starting with the general quadratic

ax%5E2%2Bbx%2Bc=0

the general solution using the quadratic equation is:

x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29



So lets solve x%5E2%2B6%2Ax-8=0 ( notice a=1, b=6, and c=-8)




x+=+%28-6+%2B-+sqrt%28+%286%29%5E2-4%2A1%2A-8+%29%29%2F%282%2A1%29 Plug in a=1, b=6, and c=-8



x+=+%28-6+%2B-+sqrt%28+36-4%2A1%2A-8+%29%29%2F%282%2A1%29 Square 6 to get 36



x+=+%28-6+%2B-+sqrt%28+36%2B32+%29%29%2F%282%2A1%29 Multiply -4%2A-8%2A1 to get 32



x+=+%28-6+%2B-+sqrt%28+68+%29%29%2F%282%2A1%29 Combine like terms in the radicand (everything under the square root)



x+=+%28-6+%2B-+2%2Asqrt%2817%29%29%2F%282%2A1%29 Simplify the square root (note: If you need help with simplifying the square root, check out this solver)



x+=+%28-6+%2B-+2%2Asqrt%2817%29%29%2F2 Multiply 2 and 1 to get 2

So now the expression breaks down into two parts

x+=+%28-6+%2B+2%2Asqrt%2817%29%29%2F2 or x+=+%28-6+-+2%2Asqrt%2817%29%29%2F2


Now break up the fraction


x=-6%2F2%2B2%2Asqrt%2817%29%2F2 or x=-6%2F2-2%2Asqrt%2817%29%2F2


Simplify


x=-3%2Bsqrt%2817%29 or x=-3-sqrt%2817%29



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Answer:

So the solutions are

x=-3%2Bsqrt%2817%29 or x=-3-sqrt%2817%29