X=-3
because
-4x=21-9
-4x= 12 divide both sides
x=-3
Answer:
189 cm^2
Step-by-step explanation:
12 cm (a) is unneeded information
8c-3d is the correct answer
Answer: 91,445,760 ft³
Step-by-step explanation:
You know that the base of this pyramid is a square, then you can use the following formula to calculate its volume:

Where "s" is the lenght of any side of the base of the pyramid and "h" is the height of the pyramid.
You know that:

Then, you can substitute these values into the formula. So, you get that the volume of The Great Pyramid is:
