The answer would be B) AD=DC, the reason why is because line AD is a reflection of line DC
Sat is the regular sat and sat II is the sat subject tests
X=1/5+2/5√14 or 1/5 + -2/5√14
They are both equal because the zeros don't count after the number 5.

The first step is to identify the order in which the equation must be solved, by following PEMDAS (you might know it as BEDMAS):
Parenthesis (or Brackets)
Exponents
Multiplication and Division
Addition and Subtraction
My advice would be to add parenthesis, following these rules, if you are not very good at finding them immediately by sight.
So:
![4 - 5 / 2 * (\frac{1}{10x}) = 1\\\\4 - [(5/2)*(\frac{1}{10x})]=1\\\\4-(2.5*\frac{1}{10x})=1\\\\4-\frac{2.5}{10x}-1=0\\3-\frac{x}{4}=0\\\frac{x}{4}=3\\x=3*4\\x=12](https://tex.z-dn.net/?f=4%20-%205%20%2F%202%20%2A%20%28%5Cfrac%7B1%7D%7B10x%7D%29%20%20%3D%201%5C%5C%5C%5C4%20-%20%5B%285%2F2%29%2A%28%5Cfrac%7B1%7D%7B10x%7D%29%5D%3D1%5C%5C%5C%5C4-%282.5%2A%5Cfrac%7B1%7D%7B10x%7D%29%3D1%5C%5C%5C%5C4-%5Cfrac%7B2.5%7D%7B10x%7D-1%3D0%5C%5C3-%5Cfrac%7Bx%7D%7B4%7D%3D0%5C%5C%5Cfrac%7Bx%7D%7B4%7D%3D3%5C%5Cx%3D3%2A4%5C%5Cx%3D12)
We check our answer:
![x=12\\4 - [(5 / 2) * (1/10)*(x)] = 1\\4 - [(5 / 2) * (\frac{1}{10}) * (12))] = 1\\4 - [2.5 * (\frac{1}{10})*12] = 1\\4 - [(\frac{2.5}{10})*12] = 1\\4 - [(\frac{1}{4})*12] = 1\\4 - 3 = 1\\1=1](https://tex.z-dn.net/?f=x%3D12%5C%5C4%20-%20%5B%285%20%2F%202%29%20%2A%20%281%2F10%29%2A%28x%29%5D%20%3D%201%5C%5C4%20-%20%5B%285%20%2F%202%29%20%2A%20%28%5Cfrac%7B1%7D%7B10%7D%29%20%2A%20%2812%29%29%5D%20%3D%201%5C%5C4%20-%20%5B2.5%20%2A%20%28%5Cfrac%7B1%7D%7B10%7D%29%2A12%5D%20%3D%201%5C%5C4%20-%20%5B%28%5Cfrac%7B2.5%7D%7B10%7D%29%2A12%5D%20%3D%201%5C%5C4%20-%20%5B%28%5Cfrac%7B1%7D%7B4%7D%29%2A12%5D%20%3D%201%5C%5C4%20-%203%20%3D%201%5C%5C1%3D1)
We are right!
So,
.