Solve 21/4-13/8

$$2 \frac { 1 } { 4 } - 1 \frac { 3 } { 8 }$$

Evaluate

$$\frac{7}{8}=0.875$$

Solution Steps

Multiply 2 and 4 to get 8.

$$\frac{8+1}{4}-\frac{1\times 8+3}{8}$$

Add 8 and 1 to get 9.

$$\frac{9}{4}-\frac{1\times 8+3}{8}$$

Multiply 1 and 8 to get 8.

$$\frac{9}{4}-\frac{8+3}{8}$$

Add 8 and 3 to get 11.

$$\frac{9}{4}-\frac{11}{8}$$

Least common multiple of 4 and 8 is 8. Convert \frac{9}{4} and \frac{11}{8} to fractions with denominator 8.

$$\frac{18}{8}-\frac{11}{8}$$

Since \frac{18}{8} and \frac{11}{8} have the same denominator, subtract them by subtracting their numerators.

$$\frac{18-11}{8}$$

Subtract 11 from 18 to get 7.

$$\frac{7}{8}$$

Factor

$$\frac{7}{2 ^ {3}} = 0.875$$