Just the image below.

1) 2x^3-2x^2+4x+20

Step-by-step explanation:

line up the equations, having each variable aligned with the similar variable, and distribute the minus sign across the parenthesis

7x^3              + 4x + 13

-(5x^3 + 2x^2          - 7)

2x^3 - 2x^2 +4x +20

answer:  

step-by-step explanation:

here x represents the height of the pole,

and, the height of the shadow of the pole is 12 feet.

also, the angle of elevation from the top of the pole is 40°,

therefore,

by the low of sine,

which is the required equation for finding the value of x,