What are the steps for adding two fractions that have the same signs?

You add the top numbers together and keep the denominator the same if the denominator is already both the same. If not, make sure the denominatoris the same first

Ex: 3/4+6/8=6/8+6/8=12/8=1 4/8=1 1/2

the height of the surface increases from the center out to the sides of the road.

step-by-step explanation:

as we move out we move away from the x-axis.

and as mentioned in the problem statement that height of a road increases when we move away from the center x.

hence proved that 3rd option

the height of the surface increases from the center out to the sides of the road.

is the correct option.