Solve -420(2/20-1/6)=

$$- 420 ( \frac { 2 } { 20 } - \frac { 1 } { 6 } ) =$$

Evaluate

$$28$$

Solution Steps

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

$$-420\left(\frac{1}{10}-\frac{1}{6}\right)$$

Least common multiple of 10 and 6 is 30. Convert \frac{1}{10} and \frac{1}{6} to fractions with denominator 30.

$$-420\left(\frac{3}{30}-\frac{5}{30}\right)$$

Since \frac{3}{30} and \frac{5}{30} have the same denominator, subtract them by subtracting their numerators.

$$-420\times \frac{3-5}{30}$$

Subtract 5 from 3 to get -2.

$$-420\times \frac{-2}{30}$$

Reduce the fraction \frac{-2}{30} to lowest terms by extracting and canceling out 2.

$$-420\left(-\frac{1}{15}\right)$$

Express -420\left(-\frac{1}{15}\right) as a single fraction.

$$\frac{-420\left(-1\right)}{15}$$

Multiply -420 and -1 to get 420.

$$\frac{420}{15}$$

Divide 420 by 15 to get 28.

$$28$$

Factor

$$2^{2}\times 7$$