## anonymous 5 years ago 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?

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).