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| ^2 + 6 + 1 | = 8 Solve equation using by factoring or using formulas

User SachinS
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1 Answer

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| x^2 + 6x+1| = 8

There are two solutions to an absolute value equation, one positive and one negative

x^2 +6x+1 =8 and x^2 +6x + 1 =-8

We have to solve both sets of equations

x^2 + 6x +1 = 8

Subtracting 8 from each side

x^2 +6x +1 -8 =0

x^2 +6x -7 =0

Factoring

What two numbers multiply to -7 and add to 6

-1 *7 = -7

-1 +7 = 6

These are the factors that we use ( -1 and 7)

( x-1) (x+7)=0

Using the zero product property

x-1 =0 x+7 =0

x=1 x=7

Now

x^2 +6x + 1 =-8

Add 8 to each side

x^2 +6x + 1+8 =0

x^2 + 6x+9 =0

Factoring

(x+3) (x+3) =0

Using the zero product property

x+3 =0 x+3 =0

x=-3

The solutions are

x=-3, x=1 , x=-7

User Mirel Vlad
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