Answer
$\frac{1}{2}, \frac{3}{7}, \frac{9}{16}$
Work Step by Step
A fraction written in the lowest terms is one that can no longer be simplified by division. For example, in 9 and 16 above: the factors of 9 are 1,3, 9 and the factors of 16 are 1, 2, 4, 8. Since none of these factors match up, there is no further factor to take out of both the numerator and the denominator.