First, we need to find the missing leg of triangle ACD. We have to use pythagorean theorem to find the missing leg.
a^2 + b^2 = c^2
In this problem,
a = 2
b = ?
c = 5
Plug our numbers into the formula above.
2^2 + b^2 = 5^2
Simplify our terms
4 + b^2 = 25
Subtract 4 from both sides
b^2 = 21
Take the square root of each side
b = √(21)
Now, we can solve for the area of triangle ABC
Area of a triangle = (h * b) / 2
h = height
b = base
In this problem,
h = √(21)
b = 5.0
Plug our numbers into the area formula of a triangle
Area = (√(21) * 5) / 2 = 11.46 square units

so.... since the number after .81 is 1, it doesn't really round up to .82, so is just that, 15.81.
We have 8^(-4) over 8^(-10). The bases are both 8, so we subtract the exponents (numerator minus denominator).

The final answer is choice C) 8^6
Answer:
no error was made
Step-by-step explanation:
5x- 1/5*(20x +5) =9
distribute
5x - 4x-1 = 9
combine like terms
x-1 =9
add 1 to each side
x-1+1 = 9+1
simplify
x = 10
11x(x+2) should be the answer