Problem 144

Since $\frac{14+1}{3+1}=\frac{15}{4}$ and $\frac{21}{4}-\frac{5}{4}-\frac{1}{4}=\frac{16}{4}-\frac{1}{4}=\frac{15}{4}$, then answers (B) and (E) both simplify to $\frac{15}{4}$.

Written as a mixed fraction, $\frac{15}{4}$ is equal to $3\frac{3}{4}$.

Since $3.75=3\frac{3}{4}=3+\frac{3}{4}$, then answers (A) and (C) both simplify to $3\frac{3}{4}$ and thus are equivalent to $\frac{15}{4}$.

Simplifying answer (D), $\frac{5}{4}\times\frac{3}{4}=\frac{5\times3}{4\times4}=\frac{15}{16}$.
Thus, $\frac{5}{4}\times\frac{3}{4}$ is not equal to $\frac{15}{4}$.