Sketch the region of integration and use an appropriate change of variables to evaluate the integral.

6.3.18. JJR + Vxy) dA, where R is the region in the first quadrant enclosed by xy = 1, xy = 9, y = x, y = 4x.6.3.20. SIR x2 sin xy dA, where R is the region enclosed by x2 = Ty/2, x2 = my, y? = x/2, y = x. y