Solve -1/4+9/10-7/20

$$- \frac { 1 } { 4 } + \frac { 9 } { 10 } - \frac { 7 } { 20 }$$

Evaluate

$$\frac{3}{10}=0.3$$

Solution Steps

Least common multiple of 4 and 10 is 20. Convert -\frac{1}{4} and \frac{9}{10} to fractions with denominator 20.

$$-\frac{5}{20}+\frac{18}{20}-\frac{7}{20}$$

Since -\frac{5}{20} and \frac{18}{20} have the same denominator, add them by adding their numerators.

$$\frac{-5+18}{20}-\frac{7}{20}$$

Add -5 and 18 to get 13.

$$\frac{13}{20}-\frac{7}{20}$$

Since \frac{13}{20} and \frac{7}{20} have the same denominator, subtract them by subtracting their numerators.

$$\frac{13-7}{20}$$

Subtract 7 from 13 to get 6.

$$\frac{6}{20}$$

Reduce the fraction \frac{6}{20} to lowest terms by extracting and canceling out 2.

$$\frac{3}{10}$$

Factor

$$\frac{3}{2 \cdot 5} = 0.3$$