1->dương vô cùng 1/x*(9+lnx^2)dx

It looks like you are trying to compute the improper integral,

or some flavor of this. If this interpretation is correct, substitute u = ln(x) and du = dx/x. Then

a4 - 3a2 - 1

step-by-step explanation:

step   1   :

equation at the end of step   1   :

  ((a4) -   3a2) -   1

step   2   :

trying to factor by splitting the middle term

2.1     factoring   a4-3a2-1  

the first term is,   a4   its coefficient is   1 .

the middle term is,   -3a2   its coefficient is   -3 .

the last term, "the constant", is   -1