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

Printable View

- Apr 8th 2010, 06:06 PMsinjid9factoring help
How do you solve (5a+3)2-10a2-6a? Which method is used for this?

- Apr 8th 2010, 06:18 PMskeeter
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 PMWilmer
- Apr 11th 2010, 11:55 AMsinjid9
why does the -2a go into the bracket?

- Apr 11th 2010, 12:48 PMWilmer
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 PMsinjid9
Then whats considered a complex trinomial 3(a+b)-a+b or a(3+b)-a+b

- Apr 11th 2010, 01:12 PMWilmer
- Apr 11th 2010, 02:41 PMsinjid9
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 PMWilmer
- Apr 11th 2010, 04:18 PMsinjid9
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 PMWilmer
Are you fooling around?

Neither is a trinomial.

Trinomial - Wikipedia, the free encyclopedia