Answer:
Volume of the cone = 
Step-by-step explanation:
Height of the cone = 
Radius of the cone = 
Volume of a cone is:

As, 
Volume is:

The volume of the cone is: 
Answer:
91
Step-by-step explanation:
7(10+3)
7(10)+7(3)
70+21
91
I've included two pictures showing steps on how to solve. Hopefully this helps more than words.
Answer:
x = 4
Step-by-step explanation:
If the lonely negative sign infront of the brackets is confusing, it can be rewritten as -1.
To solve, simplify by expanding then isolate x.
-8 = -( x +4)
-8 = -1 ( x +4) Distribute over brackets by changing the each term's sign
-8 = -x - 4 Start isolating x by moving everything to the other side
-8 +4 = -x -4 + 4 Add 4 to both sides so it cancels out on the right
-4 = -x
-4 = -1x <= -x is the same at -1x
-4/-1 = -x/-1 <=divide both sides by negative 1
4 = x
x = 4 <= usually we write the variable on the left side