SOLUTION: What are the domain restrictions of q^2+3q-4/q^2-7q-8 A. q "not equal to" 1 and q q "not equal to" -8 B. q "not equal to" -1 and q "not equal to" 8 C. q "not equal to" -1

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: What are the domain restrictions of q^2+3q-4/q^2-7q-8 A. q "not equal to" 1 and q q "not equal to" -8 B. q "not equal to" -1 and q "not equal to" 8 C. q "not equal to" -1      Log On


   

Question 932610: What are the domain restrictions of q^2+3q-4/q^2-7q-8
A. q "not equal to" 1 and q q "not equal to" -8
B. q "not equal to" -1 and q "not equal to" 8
C. q "not equal to" -1 and q "not equal to" 4
D. q "not equal to" 1 and q "not equal to" -4
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

%28q%5E2%2B3q-4%29%2F%28q%5E2-7q-8+%29 first factor completely
%28q%5E2-q%2B4q-4%29%2F%28q%5E2%2Bq-8q-8+%29
%28%28q%5E2-q%29%2B%284q-4%29%29%2F%28%28q%5E2%2Bq%29-%288q%2B8%29+%29
%28q%28q-1%29%2B4%28q-1%29%29%2F%28q%28q%2B1%29-8%28q%2B1%29+%29
%28%28q%2B4%29%28q-1%29%29%2F%28%28q%2B1%29%28q-8%29%29

domain: all values of q except those which make denominator equal to 0
%28q%2B1%29%28q-8%29=0 if %28q%2B1%29=0 or %28q-8%29=0
%28q%2B1%29=0 if q=-1
%28q-8%29=0 if q=8
so, these values are excluded from domain, and domain is
{ q element R : q%3C%3E-1 and q%3C%3E8 }
(assuming a function from reals to reals)
and your answer is B. q "not equal to" -1 and q "not equal to" 8