How in 3rd step 2a-1 is replaced by 2a-x
Solution :
we just exchanged variable t with variable x in order to match the variables as representation of variable can be with any sign.
Also,we replaced negative sign with change in limit of Integration as you can notice that limit has been reversed in the next step.
we just exchanged variable t with variable x in order to match the variables as representation of variable can be with any sign.
Also,we replaced negative sign with change in limit of Integration as you can notice that limit has been reversed in the next step.