Answer:
The greatest common factor of this would be 3x^2y
Step-by-step explanation:
In order to find this, first find the greatest common factor of the coefficients. Since 3 goes in evenly to both 15 and -18, then we know that it is a common factor.
From there we need to find the number of x's. Since the first term only has 2 x's and the second has 3, we take the lowest number. (x^2)
And since the first term has 3 y's and the second has just 1, we take the lowest number (y).
12(7x)^1/5
This is simplification into index form, the index itself is the 5th root of 7x if you just wanted to state what it is
A x = 0
using the law of exponents 
= 1
for (6² )^ x = 1 then x = 0
B note that 
= 1 ⇒ x = 1
2 → 2^8 × 3^(-5) × 1^(-2) × 3^(-8) × 2^(-12) × 2^(28)
= 2^(8 -12 + 28) × 1 × 3^(- 5 - 8)
= 2^24 × 3^(- 13) = 2^(24)/3^(13) = 10.523 ( 3 dec. places)
