how would you solve c^2+9c+18=0 because i think its non-factorable?

Question

campbell_st · Answer

there are 2 methods

1 completing the square

which requires rewriting the equation

$$c^2 + 9c = -18$$

then finding the value of (9/2)^2 and adding it to both sides

$$c^2 + 9c + \frac{81}{4} = -18 + \frac{81}{4}$$

left hand side is a perfect square and the RHS is just a number


2 using the general quadratic formula

$$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$

anonymous · Answer

thanks dude i forgot about the general quadratic formula its easier for me to use that thanks