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: 7/15
7/15 is already reduced to the lowest terms.
The numerator and denominator have no common prime factors:
- 7 is a prime number.
- 15 = 3 × 5
- GCF (7; 15) = 1
The fraction: 9/18
- The prime factorizations of the numerator and denominator:
- 9 = 32
- 18 = 2 × 32
- 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 (9; 18) = 32 = 9
9/18 = (9 ÷ 9)/(18 ÷ 9) = 1/2
The fraction can also be reduced without calculating GCF; factor the numerator and denominator and cross out all the common prime factors:
9/18 = 32/(2 × 32) = (32 ÷ 32)/((2 × 32) ÷ 32) = 1/2