Question

which expression uses a common denominator to rewrite \\(\frac{1}{4} - \frac{1}{7}\\)? \\(\frac{4}{1} - \frac{7}{1}\\) \\(\frac{7}{12} - \frac{4}{12}\\) \\(\frac{4}{28} - \frac{1}{28}\\) \\(\frac{7}{28} - \frac{4}{28}\\)

Explanation:

Step1: Find common denominator

The denominators are 4 and 7, so the least common denominator is $4×7=28$.

Step2: Rewrite fractions

$\frac{1}{4} = \frac{1×7}{4×7} = \frac{7}{28}$, $\frac{1}{7} = \frac{1×4}{7×4} = \frac{4}{28}$.

Step3: Form the expression

$\frac{1}{4} - \frac{1}{7} = \frac{7}{28} - \frac{4}{28}$.

Answer:

D. $\frac{7}{28} - \frac{4}{28}$