Lou drives at 65 mi/h. Write an expression for the number of miles that Lou drives t hours.

The expression for the number of miles that Lou drives t hours is t*65

Step-by-step explanation:

Two quantities are directly proportional when, when one of them is multiplied or divided by a number, the other is multiplied or divided respectively by the same number.  That is, the relationship between the magnitudes is direct when one magnitude increases and so does the other (or when one magnitude decreases, so does the other).

The direct rule of three is used when the problem deals with two directly proportional quantities and is used to solve proportionality problems between three known values and one unknown, establishing a proportional relationship between all of them as follows:

a ⇒ b

c ⇒ x

So

In this case the rule of three can be applied in the following way: if in 1 hour Lou travels 65 miles, in t hours how much distance does he travel?

distance=t* 65

The expression for the number of miles that Lou drives t hours is t*65

256π units²   (answer b)

step-by-step explanation:

the formula for the surface area of a sphere of radius r

is             a = 4πr²

and so, if r = 8 units, then the surface area is:

a = 4π(8 units)² = 256π units²   (answer b)

529 and 531

step-by-step explanation: