## Basic College Mathematics (10th Edition)

Estimate: 16 - 12 = 4; Exact: $4\frac{11}{15}$
$16\frac{2}{5}-11\frac{2}{3}$ Lets first Find Estimate of fraction: $16\frac{2}{5}$ = 16 and $11\frac{2}{3}$=12 $16\frac{2}{5}-11\frac{2}{3}$ = 16 - 12 = 4 Now find Exact: $16\frac{2}{5}-11\frac{2}{3}$ = $\frac{16\times5+2}{5}-\frac{11\times3+2}{3}$ = $\frac{82}{5}-\frac{35}{3}$ = $\frac{82\times3}{5\times3}-\frac{35\times5}{3\times5}$ (Least common multiple of 5 & 3 is 15) = $\frac{246}{15}-\frac{175}{15}$ = $\frac{246-175}{15}$ (Addition of fraction with same denominator) = $\frac{71}{15}$ = $4\frac{11}{15}$