How do you factor $18x^2+3x-10$ by grouping?

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Answer 1 · 2016-05-11T16:51:35

$18x^2+3x-10=(3x-2)(6x+5)$

You need to find how to split the middle term first.

Use an AC Method:

Look for a pair of factors of $AC=18*10=180$ which differ by $B=3$ .

The pair $15, 12$ works in that $15xx12=180$ and $15-12=3$ .

Use this pair to split the middle term and factor by grouping:

$18x^2+3x-10$

$=18x^2+15x-12x-10$

$=(18x^2+15x)-(12x+10)$

$=3x(6x+5)-2(6x+5)$

$=(3x-2)(6x+5)$

How do you factor 18x^2+3x-1018x^2+3x-10 by grouping?