good day. I would like to understand how to approach the following problems

52 Make a substitution to express the integrand as a rational tion and then evaluate the integral. dx dx 40. x x - 1 2vx + 3+ x dx 42. dx x2 + xx Jo + 1/x 9 3 dx dx 44. Vx2 + 1 ( 1 + 1 x ) ? dx Hint: Substitute u = /x. ] X x