Evaluate $\iint _ { R } ( x + y ) e ^ { x ^ { 2 } - y ^ { 2 } } d A$

Short Answer

Evaluate $\iint _ { R } ( x + y ) e ^ { x ^ { 2 } - y ^ { 2 } } d A$ ,where R is the rectangular region bounded by the lines x + y = 0, x + y = 1, x - y = 0, and x - y = 1.