Solve the system by substitution
-x - y - z= -8
-4x + 4y + 5z = 7
2x + 2z = 4

First:

2x + 2z = 4

2(x+z)=4

x+z=4/2

x=2-z

-x - y - z=  -8

-(2-z)-y-z= -8         replace x

-2+z-y-z= -8          (cancel z)

-2-y= -8

6 = y

Then:

-4x + 4y + 5z = 7  replace x and y

-4(2-z)+4*6 + 5z = 7

-8 + 4z + 24 + 5z = 7

16 + 9z = 7

9z = 7 - 16

9z = -9

z = -9/9

z= -1

Finally

x= 2-z  replace z

x = 2- (-1)

x = 3

(1, –1), (16, –4), (36, –6)

step-by-step explanation:

given that the function is

this can also be written as

we have to graph this function and check which list of points lie on the graph

see attachment for graph:

we find that the points lying are (1,-1) (16,-4) and (36,-6)

since square root is there we find that x can only be posiitve but y can be since square root both positive and negative.

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.