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# Factoring Algebra 2

x^4 - x^3 + 8x - 8

### 3 Answers by Expert Tutors

Robert J. | Certified High School AP Calculus and Physics TeacherCertified High School AP Calculus and Ph...
4.6 4.6 (13 lesson ratings) (13)
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x^4 - x^3 + 8x - 8

= x^3(x-1) + 8(x-1), grouping

= (x^3+8)(x-1)

= (x+2)(x^2-2x+4)(x-1), using the sum of two cubes formula: a^3+b^3 = (a+b)(a^2-ab+b^2)

Parviz F. | Mathematics professor at Community CollegesMathematics professor at Community Colle...
4.8 4.8 (4 lesson ratings) (4)
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As a rule , anytime coefficients of a polynomial add up to 0, the polynomial has root of X=1, or polynomial has factor of ( X -1 ).  That polynomial can be , by long division be divided by X -1.

Here are grouped in such a way that factoring by grouping , the (X -1) can be extracted.

By as a general rule like:

2 X5 - 3X4 + 5X3+3X2 -5X - 2 , where  ( 2 -3 + 5 + 3 - 5 -2 = 0) can be , by long division, be divided by ( X -1).
Grigori S. | Certified Physics and Math Teacher G.S.Certified Physics and Math Teacher G.S.
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You can also combime x4 and 8x and x3 with 8. You can write

x4 -x3 +8x - 8 = x(x3 +8) - (x3 +8) = (x-1)(x3 +8) = (x-1)(x+2)(x2 -2x +4)