First, we can start off by finding the greatest common factor (GCF) of the numerator and the denominator. To do this, we list the factors of each two numbers till we find the common factor that is the greatest.
Factors of 12: 1, 2, 3, 4, 6, 12
Factors of 126: 1, 2, 3, 6, 7, 9, 14, 18, 21, 42, 63, 126
Looking at the listed factors of the two numbers, which numbers are the common ones? The common factors are 1, 2, 3, and 6. We are looking for the GREATEST common factor, so out of those four numbers, which is the greatest? It is 6, so the GCF is 6.
Second, we can now divide the numerator and the denominator by the GCF (6).
Third, now we can revise our fraction in the simplified form, which we got from dividing above.
Fraction form:
Decimal form: