Let R Be the Rectangle Consisting of All Points (X $\iint _ { R } \left( e ^ { x - y } \right) d x d y$

Short Answer

Let R be the rectangle consisting of all points (x, y) such that 0 ≤ x ≤ 1, 0 ≤ y≤ 2.
Calculate $\iint _ { R } \left( e ^ { x - y } \right) d x d y$ Enter your answer exactly in the form (e - a)(1 - $\mathrm { e } ^ { \mathrm { b } }$ ).