Question

find any real numbr for which rational expression is undefined a-5/7
a. none b. a=5 c. a=o d. a=-5 i got zero is that correct?

Answer 1

You have\[a-\frac{5}{7}\]which is defined for all real numbers, a.

The answer is (a) none.

Your answer of zero would be applicable if 'a' were in the denominator (because you can't have a denominator which is zero).