Question

How do I solve c squared - c -90=0

Answer 1

Let's solve the equation, c^2 - c - 90 = 0 step by step 

Step 1: Factor left side of the equation 
(c + 9)(c - 10) = 0

Step 2: Set factors equal to zero
c + 9 = 0, or c - 10 = 0
c = -9, or c = 10

As you can see the answer is c = -9, or c = 10
Hope this helps! - Alyssa :)