Evaluate 1/3m-1-1/2n when m=21 and n=12​

There a total of 82 students in the robotics club and the science club. the science club has 6 fewer students than the robotic club. how many students are in science club?

Why can't my rank go i have 1723 points, but my rank is only at ambitious, which is only 250 points! like, (p.s. i know this isn't related to math, but i just don't know why it's doing this and i would really appreciate if someone could tell me whats going on with this)

Lucy spent $165 in december using a new credit card. in january, she began paying between $15 and $25 each month towards her account balance.