The answer is 6x³y²
Step-by-step explanation:
6x⁴y³ - 12x⁴y² + 6x³y². As you can see the common number in this expression is 6, so you can take it out :
6(x⁴y³ - 2x⁴y² + x³y²)
Next, is to take out the lowest power of a base value which is x and y. Greatest Common Factor always requires the lower power of a base value. As from the expression, the lowest power of x is 3 and for y is 2 :
6x³y²(xy - 2x + 1)