The driver of a car traveling up a 2% grade at an initial speed V0 applied the brakes abruptly and the vehicle slid to a complete stop at an average deceleration of 8 ft/s^2.
Was the pavement wet or dry?

The pavement was dry.

Explanation:

The car is modelled by means of the equations of equilibrium: (x' is for the axis parallel to the incline, y' is for the axis perpendicular to the incline)

After some algebraic handling, the following expression is constructed:

The angle of the incline is:

Now, the kinetic coefficient of friction is:

A typical kinetic coeffcient of friction between a car tire and asphalt is about 0.6, if pavement would be wet, such indicator would be significantly lower. Therefore, the deceleration occurs on dry pavement.

x+2 because it just doubles hon so the pattern can actually tell you the expression.

so for example,

if x=2 then 2+2 is 4

if x=4 then 4+4 is 8

and so on and so forth.

i really hope that this makes sense and you out in a way hon: )