# factoring help

• Apr 8th 2010, 06:06 PM
sinjid9
factoring help
How do you solve (5a+3)2-10a2-6a? Which method is used for this?
• Apr 8th 2010, 06:18 PM
skeeter
Quote:

Originally Posted by sinjid9
How do you solve (5a+3)^2-10a^2-6a? Which method is used for this?

in future, use the caret symbol (^) to denote exponents.

"factoring" the expression (not "solving") ...

\$\displaystyle (5a+3)^2 - 10a^2 - 6a
\$

\$\displaystyle (5a+3)^2 - 2a(5a + 3)\$

\$\displaystyle (5a+3)[(5a+3) - 2a]\$

\$\displaystyle (5a+3)(3a+3)\$

\$\displaystyle 3(5a+3)(a+1)\$
• Apr 8th 2010, 06:30 PM
Wilmer
Quote:

Originally Posted by sinjid9
How do you solve (5a+3)2-10a2-6a? Which method is used for this?

If you mean solve : (5a+3)^2 - 10a^2 - 6a = 0 ; then:
25a^2 + 30a + 9 - 10a^2 - 6a = 0
15a^2 + 24a + 9 = 0
Now solve for x using the quadratic formula.; you'll get 2 solutions.
• Apr 11th 2010, 11:55 AM
sinjid9
why does the -2a go into the bracket?
• Apr 11th 2010, 12:48 PM
Wilmer
Because it is being multiplied by the 1st term (5a + 3)

Try understanding this:
(5a + 3)^2 - 2a(5a + 3)
Let x = 5a + 3 ; then:
x^2 - 2ax
x(x - 2a) : kapish?
• Apr 11th 2010, 01:04 PM
sinjid9
Then whats considered a complex trinomial 3(a+b)-a+b or a(3+b)-a+b
• Apr 11th 2010, 01:12 PM
Wilmer
• Apr 11th 2010, 02:41 PM
sinjid9
Ok... but in a(3+b)-a+b does the coefficient of a in the first term affect whether it is a complex trinomial or not, or does it depend on what numbers are in the brackets?
• Apr 11th 2010, 03:07 PM
Wilmer
Quote:

Originally Posted by sinjid9
Ok... but in a(3+b)-a+b does the coefficient of a in the first term affect whether it is a complex trinomial or not, or does it depend on what numbers are in the brackets?

What are you asking? a(3 + b) - a + b = 2a + 4b , that's it.
• Apr 11th 2010, 04:18 PM
sinjid9
Which one of these is a complex trinomial
a(3 + b) - a + b or 3(a+b)-a+b
or are they both complex trinomials?
• Apr 11th 2010, 06:13 PM
Wilmer
Are you fooling around?
Neither is a trinomial.

Trinomial - Wikipedia, the free encyclopedia