Guys so I did 2u accel and got 98. Should I still do 4u since I kinda bomb the first task

. If my 4u mark is lower than my 2u will they count my 2u mark or they just gonna take the 4u math?
i was in same vote as you with 2u and also got 98 lol. i ended up doing 4u which i think slightly helped my atar. if math is your strongest subject, then i would do 4u as 4 units counting towards atar is better than 3 units.
your 4u mark may very well be lower than 2u and it will count, and your 2u will be disregarded. however, this does not necessarily make your atar worse, since now 4 units of math are counting, instead of 3, which may help a bit
also to consider is if you enjoy the content. look forward and see if it looks interesting. this was the main reason i kept 4u