Answer:
The answer would be B. When you add a negative and a positive it equals a negative, Like when adding a positive and a negative. But, adding two that are the same, like a positive and a positive equals a positive.
Step-by-step explanation:
im not 100% sure but im pretty sure it is B
Answer:
or 
Step-by-step explanation:
Substitution means plugging in one variable's value that consists of the opposite variable. Because
is already specified, you can plug it into the second equation's
value. After doing that, it looks like this:

Then you would distribute the
across the parentheses next to it, like this:

Then, add like terms, like this:

Then divide both side by
to isolate
.

Now, you can plug
(
) into either equation, but the first one seems simpler so you would pick that. It would look like this:

Solving would look like this:

So the answer is
or
.
The Formula to find the Area of a circle using the radius is:

r = 8
So:



And you get about 201.06193
So, the area of a circle with a radius of 8 is about 201.06
Hope this Helps :)
Answer:
314 m²
Step-by-step explanation:
the surface area of a sphere (As) is
As = 4×pi×r²
our radius r (half of the diameter) here is 5m.
As = 4×3.14×5² = 4×3.14×25 = 100×3.14 = 314 m²