2d - 15 =3 pls answer ASAP and with corrections

Name the most appropriate metric unit for each measurement

Weak battery is considered to be a part of routine a. inspection b. wear and tear c. maintenance d. check

1- what do you think the product of a nonzero rational number and an irrational number is? is it rational or irrational? make use of variables, the closure property of integers, and possibly a proof by contradiction to prove your hypothesis.2- why do we have to specify that the rational number must be nonzero when we determine what the product of a nonzero rational number and an irrational number is? if the rational number were 0, would it give us the same result we found in the first question?