How do you solve (5a+3)2-10a2-6a? 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
$
$\displaystyle (5a+3)^2 - 2a(5a + 3)$
$\displaystyle (5a+3)[(5a+3) - 2a]$
$\displaystyle (5a+3)(3a+3)$
$\displaystyle 3(5a+3)(a+1)$
Are you fooling around?
Neither is a trinomial.
Trinomial - Wikipedia, the free encyclopedia