Answer: 15 + 53/77
Step-by-step explanation:
Multiplying a fraction by 1 does not change the value.
Any number divided by itself is 1.
For instance, 11/11 = 7/7 = 1.
12 + 1/7 + 3 + 6/11 = 15 + 1/7 + 6/11
= 15 + (11×1)/(11×7) + (7×6)/(7×11)
= 15 + 11/77 + (6×7)/77
= 15 + (11 + 6×7)/77
= 15 + 53/77
It is faster to make sure to multiply by the "smallest" form of one that will work, but you don't have to. You only need to make sure that at the end there are no common factors in numerator and denominator, and that numerator is smaller than denominator.
