Question 22876
Use what is called the "AC Method" to factor this trinomial
In your problem a=15, b=19, c=6
Form the product ac= 90
Notice that b= 19
Now find two numbers whose product is 90 and whose sum is 19.
They are 9 and 10.
Rewrite your problem, substituting 9x + 10x in place of 19x 
to get the following:
15x^2 +9x +10x +6
Now factor the 1st two terms and then the last two terms as follows:
3x(5x+3)2(5x+3)
= (5x+3)(3x+2

By the way.  If there are not two numbers whose product is AC and
whose sum is B you will have to use the binomial formula to find 
the factors.

Cheers,
Stan H.