help
posted by Katie .
find all numbers for which the rational expression is undefinded
8/8z+7
I think the expression is undefined for all real numbers

If the fraction is 8/(8z) + 7 you are right.
If it is 8/(8z+7) then the answer is different. 
Oops. If 8/(8z) + 7, then it is undefined only for z=0
In general, a rational expression is undefined where the denominator is zero. 
Thank you steve

My pleasure. Now, go forth and solve similar problems with confidence!

I will try my best