How do you factor #x^2-7x-18#?
1 Answer
Explanation:
First step, we need to split the equation up into factors that will multiply back into the given quadratic.
What times
#x * x# , of course.
So, that gives us factors of
#(x" ")(x" ")#
Now we need two numbers that will multiply into
The factors of
#(-9)(+2) = -18 " "# and#" " -9 + 2 = -7#
Therefore
#= x^2-7-18#
#= (x -9)(x+2)#
Always look for the operator signs as a helping indicator.
Hope this helps.