Question 829945

Can someone please show me the steps to factor a trinomial? It's for college Algebra. 

Factor the trinomial or state that the trinomial is prime.

5a^2 -4a-28<pre>
Apply the "ac" method
From the trinomial, {{{5a^2 - 4a - 28}}},
a = 5
b = - 4
c = - 28

ac = 5(- 28), or - 140
As "ac" = - 140, and b = - 4, we need to determine which 2 numbers have a product of - 140, and sum to b, or - 4

These 2 numbers are: + 10 and - 14
{{{5a^2 + 10a - 14a - 28}}} ----- Replacing - 4a with (10a - 14a)
{{{5a(a + 2) - 14(a + 2)}}} ------ Factoring each pair of expressions
{{{highlight_green((5a - 14)(a + 2))}}}
You can do the check!! 

Send comments, “thank-yous,” and inquiries to “D” at MathMadEzy@aol.com.
Further help is available, online or in-person, for a fee, obviously. 
	
For FREE info and answers to questions about the ASVAB exam, the NYS 3 – 8 city/state wide exams, 
GENERAL MATH QUESTIONS, MATH HOMEWORK QUESTIONS, or MATH QUESTIONS related to the Regents Integrated Algebra,
Regents Geometry, Regents Algebra 2/Trigonometry, SHSAT, COOP/HSPT/TACHS, PSAT, SAT, ACT, SSAT/ISEE, GRE, CLEP,
and the GED, you can visit: http://asvabstudyzone.freeforums.net/.