Answer: 
Step-by-step explanation:
For this exercise you need to use the following formula for calculate the area of regular polygon:

Where is "s" the length of any side, "n" is the number of sides.
Int this case you know that it is regular pentagon, which means that it has five sides. Then you can identify that the values of "n" and "s":

Therefore, substituitng values into the formula, you get that the area f the pentagon is:

Answer:
The value of the expression at x=5 is 10
Step-by-step explanation:
The given expression is 
Let us simplify this expression.
Distribute -2 over the parentheses, we get

Now, substitute x = 5, we get

On simplifying, we get

The value of the expression at x=5 is 10
Answer:
=10x2−8
Step-by-step explanation:
4(x2−5)+2(3x2+6)
Distribute:
=(4)(x2)+(4)(−5)+(2)(3x2)+(2)(6)
=4x2+−20+6x2+12
Combine Like Terms:
=4x2+−20+6x2+12
=(4x2+6x2)+(−20+12)
=10x2+−8
https://jhmsmath.weebly.com/uploads/2/7/7/5/27756807/8th_grade_countdown.pdf go to this link page 52-54