Answer
True, $\frac{14}{5}$
Work Step by Step
We can determine whether or not each proportion is true by writing both sides of the proportion with the same denominator. If both sides also have the same numerator when written as like fractions, we know that the proportion is true.
Left side: $\frac{42}{15}=\frac{42\div3}{15\div3}=\frac{14}{5}$
Right side: $\frac{28}{10}=\frac{28\div2}{10\div2}=\frac{14}{5}$
Therefore, both sides of the proportion are equal to each other, so the proportion is true.
