Which could be the resulting equation when elimination is used to solve the given system of equations ?

10·b = 60

Step-by-step explanation:

The given system of equation is presented as follows;

5·a + 5·b = 25...(1)

-5·a + 5·b = 35...(2)

Given that the coefficient of a in equation (1) is equal in magnitude but opposite in sign to the coefficient of 'a' in equation (2), to eliminate the variable 'a' when using the elimination method, we add both equations as follows;

5·a + 5·b + (-5·a + 5·b) = 25 + 35 = 60

5·a - 5·a + 5·b + 5·b = 60

5·a - 5·a = 0

5·b + 5·b = 10·b

∴ 5·a - 5·a + 5·b + 5·b = 60 = 0 + 10·b = 10·b

∴ 10·b = 60

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.