Can someone help me understand what this student was trying to do? I need an explanation as for a 10 year old kid.

Find the integral. (b ) ax x 1/ 9 x 2-4 - = t x2 d x = dt * 7 9 x 2- 4 dx = 1 X N 9 - 4 *z dx = - dt * 2 = dt 1 X = dt 2 19 - + 2 1/ 9 - 4+ 2 = 2 (32 ) 12 - + 2 = - - sin 3 + c E sin 2 ( 2 2 ) + C - 1 2 2 sin 3 x + C what student got