**Answer:**

a) The independent variable is r, the radius. You can use any allowable number for r. The dependent variable is V, the volume. Once you choose a value for r, the value of V will depend on that value of r.

b) The domain is all real numbers greater than 0. A radius cannot be zero or a negative number.

c) The output of V(8) is the function V(r) evaluated at r = 8, so it is the volume of a sphere of radius 8 units.

A) Less, because if you multiply 1 x 12 you get you get 12, then if you multiply by a decimal less than 1 you will get a product that is less than 12.

B) More, because you are not multiplying by a smaller number like 0.07 it still has 2 digits so it would probably be more than 1.

**Answer:**

Yes for:

x = 30

**Step-by-step explanation:**

Since 31 = x+1

Simplifying, 1 is deducted from 31 to get 30

This gives the two sides of the equation as 30 = x

Therefore, x = 30

This is a simple equation. It can easily calculate the value of x given the value on the other side of the equation. Therefore, x is a dependent variable in this system of equation. And just like every system of equation, the simple equation problem requires that the two sides of the equation are always kept in balance or equilibrium.