Answer is C but can't figure it out.

C. 2,940 ft³

Step-by-step explanation:

The building is composed of a triangular prism and a rectangular prism

Therefore,

Volume of air in the building = volume of the triangular prism + volume of the rectangular prism

Volume of triangular prism = ½*bhl

b = 4 yards = 4*3 = 12 ft

h = 15 - 9½ = 5½ = 5.5 ft

l = 20 ft

Volume of triangular prism = ½*12*5.5*20 = 660 ft³

Volume of rectangular prism = W*H*L

W = 4 yds = 12 ft

H = 9½ = 9.5

L = 20 ft

Volume of rectangular prism = 12*9.5*20 = 2,280 ft³

✔️Volume of air in the building = 660 + 2,280 = 2,940 ft³

(x3 + 6x2 + 2x - 6) • (x - 1)

step-by-step explanation:

polynomial long division :

3.2     polynomial long division

dividing :   x4+5x3-4x2-8x+6

                              ("dividend")

by         :     x-1     ("divisor")

dividend     x4   +   5x3   -   4x2   -   8x   +   6

- divisor   * x3     x4   -   x3            

remainder         6x3   -   4x2   -   8x   +   6

- divisor   * 6x2         6x3   -   6x2        

remainder             2x2   -   8x   +   6

- divisor   * 2x1             2x2   -   2x    

remainder               -   6x   +   6

- divisor   * -6x0               -   6x   +   6

remainder                     0

quotient :   x3+6x2+2x-6   remainder:   0