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: - 35/78
- 35/78 is already reduced to the lowest terms.
The numerator and denominator have no common prime factors:
- 35 = 5 × 7
- 78 = 2 × 3 × 13
- GCF (35; 78) = 1
The fraction: - 42/84
- The prime factorizations of the numerator and denominator:
- 42 = 2 × 3 × 7
- 84 = 22 × 3 × 7
- 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 (42; 84) = 2 × 3 × 7 = 42
- 42/84 = - (42 ÷ 42)/(84 ÷ 42) = - 1/2
The fraction can also be reduced without calculating GCF; factor the numerator and denominator and cross out all the common prime factors:
- 42/84 = - (2 × 3 × 7)/(22 × 3 × 7) = - ((2 × 3 × 7) ÷ (2 × 3 × 7))/((22 × 3 × 7) ÷ (2 × 3 × 7)) = - 1/2