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7X²-26X-8=0
Solving polynomial equations with factoring, algebra. Please help me!

1 Answer

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Answer:
\bold{x=\bigg\{4,-(2)/(7)}\bigg\}

Explanation:

7x² - 26x - 8 = 0

Find two numbers whose product equals (7)(-8) and sum equals -26.

-28 × 2 = 56, -28 + 2 = -26

Replace -26x with -28x + 2x: 7x² - 28x + 2x - 8 = 0

Factor the left two terms & right two terms: 7x(x - 4) + 2(x - 4) = 0

Notice that both sides have a common factor of (x - 4) --> This is one of the factors. The other factor is what is on the outside of (x - 4) --> 7x + 2

Rewrite the expression as two factors: (x - 4)(7x + 2) = 0

set each factor equal to zero and solve for x.

x - 4 = 0 7x + 2 = 0

x = 4 7x = -2

x
=-(2)/(7)

User Sunil Kanzar
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