Anonymous
Anonymous asked in Science & MathematicsMathematics · 9 years ago

# Factor completely: 8x^2 + 72x + 112?

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8x² + 72x = - 112

x² + 9/2x = - 14 + (9/2)²

x² + 9/2x = (- 56 + 81)/4

(x + 9/2)² = 25/4

x + 9/2 = ± 5/2

= x + 9/2 - 5/2, = x + 4/2, = x + 2

= x + 9/2 + 5/2, = x + 14/2, = x + 7

Answer: 8(x + 2)(x + 7)

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• Hi

8x^2 + 72x + 112=0

==> 2x^2 + 18x +28=0

==> x^2 + 9x +14 =0

2*7=14 and 2 + 7=9 then

(x+9)(x+2)=0

thus

8x^2 + 72x + 112=8(+9)(x+2)

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• 8x^2 + 72x + 112

8x^2 + 16 x + 56 x + 112 (112x8 =56x2x4x2=56x16)

8x (x + 2 ) + 56 ( x +2)

(8x+56)(x+2)

8(x+7)(x+2)

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• Anonymous
9 years ago

First factor 8 out:

= 8(x^2+9x+14)

= 8(x+7)(x+2)

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• Anonymous
9 years ago

Factor 8 out: 8(x^2 + 9x + 14)

Now use FOIL: 8(x+7)(x+2) <======= Answer

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• 8x^2 + 72x + 112

8 (2 + x) (7 + x)

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• Anonymous
9 years ago

That is not a question, it's an order.

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