X² - 4x +40=0
how do i solve this

x = 2 + 6i, x - 6i.

Step-by-step explanation:

To factor this you need 2 numbers whose product is + 40 and whose sum is -4. There are no such numbers so we could use the method of completing the square:

x^2 - 4x + 40 = 90

x^2 - 4x = -40

(x - 2)^2 - 4 = -40

(x - 2)^2 = -36     -  So the roots are complex numbers:

x - 2 = +/-√36

x = 2 + 6i, x - 6i.

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.