help me w my math pls (AGAIN)

i dont regret being annoying here i rlly need help w my calc ,, (math ques is in the comments) i photo mathed it but cant seem to grasp the process?? if its ok someone can explain it to me...


also, i actually do my hw i dont rely on mangago users much lmao... i also dont want to use photomath and call it a day-- exams are near and i genuinely want to learn. the prof might actually just teach this at thursday but i should be studying NOW bc exams r nxt week so help.