Which are differences of perfect cubes? check all that apply.

9a3 – 27

125a12 – 72

216a6 – 27y3

8a15 – 27

225a3 – 216

we know that

A perfect cube is a whole number which is the cube of another whole number

so

A number is a perfect cube, if the cubic root of the number is equal to a whole number

case 1)

in this problem the cubic root of is not a whole number

therefore

The case 1) is not a differences of perfect cubes

case 2)

in this problem the cubic root of is not a whole number

therefore

The case 2) is not a differences of perfect cubes

case 3)

therefore

The case 3) is a differences of perfect cubes

case 4)

therefore

The case 4) is a differences of perfect cubes

case 5)

therefore

The case 5) is a differences of perfect cubes

therefore

the answer is

point a is the center of the circle that passes through points e, f, and g and the center of the circle that passes through points x, y, and z.