|AC| = 2|DE|
⇒
4x - 2 = 2(x + 6) = 2x + 12
2x = 14
x = 7
⇒
|AC| = 26
Answer:
B. 300
Step-by-step explanation:
Final figure volume = big cuboid volume - small cuboid volume
Volume of a cuboid = height x width x length
Final figure = (6 x 6 x 15) - (4 x 4 x 15)
Final figure = 540 - 240
Final figure = 300mm^2
If 5/6 gallons covers a quarter of the house, then you would need 4 times as much paint:

Which is 20/6 gallons or 3 and 1/3 gallons
Hope this helped