SOLUTION: I am having a hard time with this, can someone help me please? Rewrite the middle term as the sum of two terms and then factor completely. 15x2 – 21x + 6

You can put this solution on YOUR website!
15x2 – 21x + 6
This is called the "ac" method of factoring.
You want to find two numbers whose product is ac=(15)(6)=90
and whose sum is b=-21
The numbers are -15 and -6.
Rewrite the problem using -15x -6x in place of -21x, as follows:
15x^2-15x-6x+6
Now factor by grouping as follows:
15x(x-1)-6(x-1)
(x-1)(15x-6)
That's it.
Cheers,
Stan H.