Solve 13/30-16/55-9/40

$$\frac { 13 } { 30 } - \frac { 16 } { 55 } - \frac { 9 } { 40 }$$

Evaluate

$$-\frac{109}{1320}\approx -0.082575758$$

Solution Steps

Least common multiple of 30 and 55 is 330. Convert \frac{13}{30} and \frac{16}{55} to fractions with denominator 330.

$$\frac{143}{330}-\frac{96}{330}-\frac{9}{40}$$

Since \frac{143}{330} and \frac{96}{330} have the same denominator, subtract them by subtracting their numerators.

$$\frac{143-96}{330}-\frac{9}{40}$$

Subtract 96 from 143 to get 47.

$$\frac{47}{330}-\frac{9}{40}$$

Least common multiple of 330 and 40 is 1320. Convert \frac{47}{330} and \frac{9}{40} to fractions with denominator 1320.

$$\frac{188}{1320}-\frac{297}{1320}$$

Since \frac{188}{1320} and \frac{297}{1320} have the same denominator, subtract them by subtracting their numerators.

$$\frac{188-297}{1320}$$

Subtract 297 from 188 to get -109.

$$-\frac{109}{1320}$$

Factor

$$-\frac{109}{1320} = -0.08257575757575758$$