6. +-/1 points SCalcET7 15.10.024. Evaluate the integral by making an appropriate change of variables. LLk 3(x + y) ex² - y2 dA, where R is the rectangle enclosed by the lines x - y = 0, x - y = 7, x + y = 0, and x + y = 3 Need Help? Read It Talk to a Tutor 7. -/1 points SCalcET7 15.10.026. Evaluate the integral by making an appropriate change of variables. √ 4 sin (9x² + 36y²) dA, where R is the region in the first quadrant bounded by the ellipse 9x² + 36y² = 1 JR Need Help? Read It Talk to a Tutor