Answer: g = -2
x = 5
Step-by-step explanation:
If the diameter is 8 centimeters, the radius is 4. We can use the formula

and plug in r=4 and h=13 to get

, so

.
Let Amanda's age = x.
Gregory's age = x + 5.
Since Gregory is 17 years old.
17 = x + 5
x = 17 - 5
x = 12
Amanda is 12 years old.