Solve 9/10-51/4-33/8

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

Evaluate

$$-\frac{309}{40}=-7.725$$

Solution Steps

Multiply 5 and 4 to get 20.

$$\frac{9}{10}-\frac{20+1}{4}-\frac{3\times 8+3}{8}$$

Add 20 and 1 to get 21.

$$\frac{9}{10}-\frac{21}{4}-\frac{3\times 8+3}{8}$$

Least common multiple of 10 and 4 is 20. Convert \frac{9}{10} and \frac{21}{4} to fractions with denominator 20.

$$\frac{18}{20}-\frac{105}{20}-\frac{3\times 8+3}{8}$$

Since \frac{18}{20} and \frac{105}{20} have the same denominator, subtract them by subtracting their numerators.

$$\frac{18-105}{20}-\frac{3\times 8+3}{8}$$

Subtract 105 from 18 to get -87.

$$-\frac{87}{20}-\frac{3\times 8+3}{8}$$

Multiply 3 and 8 to get 24.

$$-\frac{87}{20}-\frac{24+3}{8}$$

Add 24 and 3 to get 27.

$$-\frac{87}{20}-\frac{27}{8}$$

Least common multiple of 20 and 8 is 40. Convert -\frac{87}{20} and \frac{27}{8} to fractions with denominator 40.

$$-\frac{174}{40}-\frac{135}{40}$$

Since -\frac{174}{40} and \frac{135}{40} have the same denominator, subtract them by subtracting their numerators.

$$\frac{-174-135}{40}$$

Subtract 135 from -174 to get -309.

$$-\frac{309}{40}$$

Factor

$$-\frac{309}{40} = -7\frac{29}{40} = -7.725$$