In order to find zeroes of a function, we will probably want to use our quadratic formula.
-b±√b^2-4(a)(c)/2a
If we know our values, we can plug it in.
Our values:
A=1 (Since there is no number in front of x, it is an assumed 1)
B=17
C=72
Now, We can plug it into our formula.
BE SURE TO PUT PARENTHESIS AROUND ALL TERMS!
-(17)±√(17)^2-4(1)(72)/2(1)
Now we can type it into a calculator!
When we plug it into the formula. It gives us two real solutions (or zeroes) which are represented as:
-8 & -9.