Evaluate the integral by making an appropriate change of variables. 3 ( x + y ) ex - y2 dA, where R is the rectangle enclosed by the lines x - y = 0, x - y = 4, x + y = 0, and x + y = 3 X Need Help? Read It Submit AnswerWe have to Evaluate (/ 3 ( xty ) . 2 = yz dA R where R. the rectangle enclosed by the lines x - y=0 ; x - 4 = 4 ; xty = 0 and x+ y = 3 Making the change of variables Let x - y = u and aty = 19 utv = 2 20 3 21 = utz 2 and Vu = 24 7 V - u The Jacobian Matrix is J . 4 + 4 = ay ay Now Evaluating re = 4 2 (1 3 ( x ty ) * = yz - o'dA = 1 1 3 ( x ty ) e 15 / dudu R R' where R ' = S( uin) : 0