The equations of the line and the curve are as follows:
line = 2 x - 1
eq = Sin[x + 2 y] == 2 x - y;
I solved the problem using the following Mathematica code—does anyone have a better (or simply different) approach?
F[x_, y_] := Sin[x + 2 y] - 2 x + y;
dydx[x_, y_] = -D[F[x, y], x]/D[F[x, y], y] // Simplify
eqs = {F[x, y] == 0, dydx[x, y] == 2 };
sol = NSolve[eqs, {x, y}, Reals]