Answer:
(15x + 120) ft³
Or
15(x + 8) ft³
Explanation:
The prism can be decomposed into a rectangular prism and a triangular prism
The volume of the prism = volume of the rectangular prism + volume of the triangular prism
✔️Volume of rectangular prism = L*W*H
L = 5 ft
W = 4 ft
H = 6 ft
Volume = 5*4*6 = 120 ft³
✔️Volume of triangular prism = ½*b*h*l
b = x ft
h = 6 ft
l = 5 ft
Volume = ½*x*6*5 = 15x ft³
✔️Volume of the prism = (15x + 120) ft³