Question 253100
x^2 - x = 110.
x^2 - x - 110 = 0.
To factor this, what two numbers multiply to -110 but add up to -1?  The answer is -11 and 10, so:
(x-11)*(x+10)=0
Solving this equation, we get: x = 11 and x = -10.  Choose the negative solution: x=-10.