Problem of the Week

Updated at Nov 9, 2020 10:43 AM

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Mar 24, 2025

This week we have another algebra problem:

How would you find the factors of $28{x}^{2}+13x-6$ ?

Let's start!

28{x}^{2}+13x-6

Split the second term in

28{x}^{2}+13x-6

into two terms.

Multiply the coefficient of the first term by the constant term.

28\times -6=-168

Ask: Which two numbers add up to

13

and multiply to

-168

21

and

-8

Split

13x

as the sum of

21x

and

-8x

28{x}^{2}+21x-8x-6

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28{x}^{2}+21x-8x-6

Factor out common terms in the first two terms, then in the last two terms.

7x(4x+3)-2(4x+3)

Factor out the common term

4x+3

(4x+3)(7x-2)

Done