Simplify the operation
Reduce (simplify) the fractions to their lowest terms equivalents:
- To reduce a fraction to the lowest terms equivalent: divide both the numerator and denominator by their greatest common factor, GCF.
The fraction: 20/78
- The prime factorizations of the numerator and denominator:
- 20 = 22 × 5
- 78 = 2 × 3 × 13
- Multiply all the common prime factors: if there are repeating prime factors we only take them once, and only the ones having the lowest exponent (the lowest powers).
- GCF (20; 78) = 2
20/78 = (20 ÷ 2)/(78 ÷ 2) = 10/39
The fraction can also be reduced without calculating GCF; factor the numerator and denominator and cross out all the common prime factors:
20/78 = (22 × 5)/(2 × 3 × 13) = ((22 × 5) ÷ 2)/((2 × 3 × 13) ÷ 2) = 10/39
The fraction: 28/84
- 28 = 22 × 7
- 84 = 22 × 3 × 7
- GCF (28; 84) = 22 × 7 = 28
28/84 = (28 ÷ 28)/(84 ÷ 28) = 1/3
The fraction can also be reduced without calculating GCF; factor the numerator and denominator and cross out all the common prime factors:
28/84 = (22 × 7)/(22 × 3 × 7) = ((22 × 7) ÷ (22 × 7))/((22 × 3 × 7) ÷ (22 × 7)) = 1/3