A3. For real numbers $x$ and $y$, it is given that $\frac{x}{x+y}=101$. What is the value of the expression $\frac{y-x}{y}$?
(A) 1.02
(B) 100
(C) 201
(D) 2.01
(E) 1.01
A3. Multiply the equality by the denominator and express $x=-1.01 y$, then substitute this into the expression $\frac{y-x}{y}=$ $\frac{y+1.01 y}{y}=\frac{2.01 y}{y}=2.01$.