SOLUTION: List all numbers for which the rational expression is undefined. x^2-9 / x^2+3x-18 A. -3, 6 B. -6, 3 C. -3, 3 D. 0

Algebra ->  Complex Numbers Imaginary Numbers Solvers and Lesson -> SOLUTION: List all numbers for which the rational expression is undefined. x^2-9 / x^2+3x-18 A. -3, 6 B. -6, 3 C. -3, 3 D. 0       Log On


   

Question 303237: List all numbers for which the rational expression is undefined.
x^2-9 / x^2+3x-18
A. -3, 6
B. -6, 3
C. -3, 3
D. 0

Found 2 solutions by london maths tutor, Fombitz:
Answer by london maths tutor(243) About Me  (Show Source):
You can put this solution on YOUR website!
%28x-3%29%28x%2B3%29%2F%28%28x%2B6%29%28x-3%29%29
=%28x%2B3%29%2F%28x%2B6%29
Answer B -6, 3

Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Simplify first.
%28x%5E2-9%29%2F%28x%5E2%2B3x-18%29=%28%28x%2B3%29%28x-3%29%29%2F%28%28x%2B6%29%28x-3%29%29

%28x%5E2-9%29%2F%28x%5E2%2B3x-18%29=%28x%2B3%29%2F%28x%2B6%29
The expression is undefined when the denominator equals zero.
x%2B6=0
x=-6
.
.
.
The correct answer is not available as a choice.
.
.
.
+graph%28+300%2C300%2C+-10%2C+10%2C+-10%2C+10%2C+%28x%5E2-9%29%2F%28x%5E2%2B3x-18%29%29+