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: 891/912
- The prime factorizations of the numerator and denominator:
- 891 = 34 × 11
- 912 = 24 × 3 × 19
- 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 (891; 912) = 3
891/912 = (891 ÷ 3)/(912 ÷ 3) = 297/304
The fraction can also be reduced without calculating GCF; factor the numerator and denominator and cross out all the common prime factors:
891/912 = (34 × 11)/(24 × 3 × 19) = ((34 × 11) ÷ 3)/((24 × 3 × 19) ÷ 3) = 297/304
The fraction: 894/915
- 894 = 2 × 3 × 149
- 915 = 3 × 5 × 61
- GCF (894; 915) = 3
894/915 = (894 ÷ 3)/(915 ÷ 3) = 298/305
The fraction can also be reduced without calculating GCF; factor the numerator and denominator and cross out all the common prime factors:
894/915 = (2 × 3 × 149)/(3 × 5 × 61) = ((2 × 3 × 149) ÷ 3)/((3 × 5 × 61) ÷ 3) = 298/305
Calculate the common numerator
The common numerator is nothing else than the least common multiple (LCM) of the numerators of the fractions.
To calculate the LCM, we need the prime factorization of the numerators:
297 = 33 × 11
298 = 2 × 149
Multiply all the unique prime factors: if there are repeating prime factors we only take them once, and only the ones having the highest exponent (the highest powers).
LCM (297, 298) = 2 × 33 × 11 × 149 = 88,506
Calculate the expanding number of each fraction:
Divide the LCM by the numerator of each fraction.
297/304 ⟶ 88,506 ÷ 297 = (2 × 33 × 11 × 149) ÷ (33 × 11) = 298
298/305 ⟶ 88,506 ÷ 298 = (2 × 33 × 11 × 149) ÷ (2 × 149) = 297
Make the numerators of the fractions the same:
- Expand each fraction: multiply both its numerator and denominator by its corresponding expanding number, calculated above.
- This way all the fractions will have the same numerator:
297/304 = (298 × 297)/(298 × 304) = 88,506/90,592
298/305 = (297 × 298)/(297 × 305) = 88,506/90,585