Question 53678
6x^2+-1x-12 
I'll show you the AC method of factoring.
In your problem A=6,B=-1,C=-12
A*C=6(-12)=-72
B=-1
You need to think of two numbers whose product is -72
and whose sum is -1
The numbers are -9 and 8
So you rewrite the problem as follows:
6x^2-9x+8x-12
Now factor the 1st two terms and the last two terms separately, as follows:
3x(2x-3)+4(2x-3)
Factor again to get:
(2x-3)(3x+4)
---------------
AND
6x^2 -17x-12
AC=-72
B=-17
There are no two whole numbers whose product is -72 and sum is -17.
I suspect you didn't post this problem correctly.
To factor this problem you would have to use the quadratic formula.
AND
x^2+-3x+10
AC=10
B=-3
Similarly, you would have to use the quadratic formula to factor 
this problem.
cheers,
Stan H.