Factor by Grouping (ac method)

Question

28x²-x-2

First choose a form with appropriate signs. Then, fill in the blanks with numbers used for grouping. Finally, show the factorization.

Form:

28x² + ? X + ? X - 2

28x² + ? X - ? X - 2

28x² - ? X + ? X - 2

28x² - ? X - ? X - 2

Factorization:

Answer 1

Hello chan just add the columns: Then factor.

_{28x^2 + ?x + ?x -2}

_{28x^2 +?x -?x -2}

_{28x^2 -?x + ?x -2}

_{28x^2 -?x -?x -2}

_{____________________________________ Add each column.}

_{112x^2 +0x +0x -8 ( when columns are added).}

_{= 112x^2 -8 ( Now factor out a -8) Giving:}

_{-8 ( -14x ^2 +1) Now use the Quadratic Formula.}

_{X1 = + 1 √14}

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_{(I tried to type this out clear Hope this helps)}

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