15. The intensity of light at its source is 100%. The intensity, I, at a distance d centimetres from
the source is given by the formula I = 100d-2.
Use the formula to determine the intensity of
the light 23 cm from the source.

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?