$y^{\prime \prime}-y=0$
\(\boxed{y(x) = C_1 e^{-x} + C_2 e^{x}}\)
Step 1 :Assume a solution of the form: \(y = e^{rx}\)
Step 2 :Substitute into the equation and solve for r: \(r^2 - 1 = 0\)
Step 3 :Find the values of r: \(r = -1, 1\)
Step 4 :Write the general solution: \(y(x) = C_1 e^{-x} + C_2 e^{x}\)
Step 5 :\(\boxed{y(x) = C_1 e^{-x} + C_2 e^{x}}\)