Numbers first: 3, 12, 10
3 = 3
12 = 2 * 2 * 3
10 = 2 * 5
Make a pool of prime factors that has enough pieces to make each of (3, 12, 10). 2 * 2 * 3 * 5 = 60
x^2 = x * x
x^3 = x * x * x
The smallest thing that x^2 and x^3 will go into is x^3.
y = y
y^3 = y * y * y
The smallest thing that y and y^3 will go into is y^3.
Answer: 60 x^3 y^3