Solve 39/10-21/8+14/5

$$3 \frac { 9 } { 10 } - 2 \frac { 1 } { 8 } + 1 \frac { 4 } { 5 }$$

Evaluate

$$\frac{143}{40}=3.575$$

Solution Steps

Multiply 3 and 10 to get 30.

$$\frac{30+9}{10}-\frac{2\times 8+1}{8}+\frac{1\times 5+4}{5}$$

Add 30 and 9 to get 39.

$$\frac{39}{10}-\frac{2\times 8+1}{8}+\frac{1\times 5+4}{5}$$

Multiply 2 and 8 to get 16.

$$\frac{39}{10}-\frac{16+1}{8}+\frac{1\times 5+4}{5}$$

Add 16 and 1 to get 17.

$$\frac{39}{10}-\frac{17}{8}+\frac{1\times 5+4}{5}$$

Least common multiple of 10 and 8 is 40. Convert \frac{39}{10} and \frac{17}{8} to fractions with denominator 40.

$$\frac{156}{40}-\frac{85}{40}+\frac{1\times 5+4}{5}$$

Since \frac{156}{40} and \frac{85}{40} have the same denominator, subtract them by subtracting their numerators.

$$\frac{156-85}{40}+\frac{1\times 5+4}{5}$$

Subtract 85 from 156 to get 71.

$$\frac{71}{40}+\frac{1\times 5+4}{5}$$

Multiply 1 and 5 to get 5.

$$\frac{71}{40}+\frac{5+4}{5}$$

Add 5 and 4 to get 9.

$$\frac{71}{40}+\frac{9}{5}$$

Least common multiple of 40 and 5 is 40. Convert \frac{71}{40} and \frac{9}{5} to fractions with denominator 40.

$$\frac{71}{40}+\frac{72}{40}$$

Since \frac{71}{40} and \frac{72}{40} have the same denominator, add them by adding their numerators.

$$\frac{71+72}{40}$$

Add 71 and 72 to get 143.

$$\frac{143}{40}$$

Factor

$$\frac{11 \cdot 13}{2 ^ {3} \cdot 5} = 3\frac{23}{40} = 3.575$$