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44 votes
44 votes
7x^2+16-8

Solve using the Quadradic Formula, and round to the nearest hundredth as needed.

Someone please help-

User Tvb
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2 Answers

10 votes
10 votes

Answer: 0.45 and -2.74

Explanation:

You're going to want to use the Quadratic Formula, so (-b±√(b^2-4ac))/2a.

When you plug in you should get -16 ± √16^2-4(7)(-8)/2(7)

-16± √(256+224) all divided by 2 x 7 or 14

(-16 ± 22.3607)/14

0.45 and -2.74 are your answers

User Sajid Ahmad
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16 votes
16 votes
First step (7x2 - 16x) - 8 = 0
Second step Factoring 7x2-16x-8

The first term is, 7x2 its coefficient is 7 .
The middle term is, -16x its coefficient is -16 .
The last term, "the constant", is -8

Step-1 : Multiply the coefficient of the first term by the constant 7 • -8 = -56

Step-2 : Find two factors of -56 whose sum equals the coefficient of the middle term, which is -16 .
All of that said it’ll be 2.708
How I got 2.708 is x =(16+√480)/14=(8+2√ 30 )/7= 2.708
And 0.422 is x =(16-√480)/14=(8-2√ 30 )/7= -0.422
User Ilya Boyandin
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