Subtract and simplify.
-$18 \frac { 3 } { 7 } - \frac { 11 } { 21 }$
A)17
B) $16 \frac { 19 } { 21 }$
C) $18 \frac { 19 } { 21 }$
D) $17 \frac { 19 } { 21 }$

Question

Quizplus · Accepted Answer

First, convert $18 \frac{3}{7}$ to an improper fraction: $18 \frac{3}{7} = \frac{126}{7} + \frac{3}{7} = \frac{129}{7}$. Then, subtract $\frac{11}{21}$ from $\frac{129}{7}$. Since $7$ and $21$ have a common denominator of $21$, convert $\frac{129}{7}$ to have a denominator of $21$: $\frac{129}{7} = \frac{129 \times 3}{7 \times 3} = \frac{387}{21}$. Subtracting gives $\frac{387}{21} - \frac{11}{21} = \frac{376}{21}$, which simplifies to $17 \frac{19}{21}$.

Subtract and Simplify 1837−112118 \frac { 3 } { 7 } - \frac { 11 } { 21 }1873​−2111​

Subtract and Simplify $18 \frac { 3 } { 7 } - \frac { 11 } { 21 }$