7th grade math help me pleaseee :)

answer of 2a)

He started with $24 and spent $16. Let a represent his account balance after he bought the notebook and pens. Then

24–16=a

His new account balance is $8.

He has $8 in his account and then he deposited b dollars. His account balance is now $28. Then

8+b=28

His deposited $20 in his account.

He has $28 and spent $34. Let c represent his account balance after he bought the book. Then

28–34=c

His new account balance is -$6.

He started with an account balance of -$6 and paid the debt off so his account balance is 0. If d is the amount money he deposited to pay off his debt, then

−6+d=0

He deposited $6.

answer of 2b)

If he spends more than he has in his account, then we are subtracting a bigger number from a smaller number, and the result is negative. ... The opposite of a positive number is a negative number, so it makes sense to represent his account balance with a negative number when he owes money to the bookstore.

please give me brainliest:))

the figures below are made out of circles, semicircles, quarter … find the area and the perimeter of each figure and give your answers as a completely simplified exact value in terms of π (no approximations). remember that we'll also have to cut whatever areas we get in half, since we're only dealing im pretty sure that is the right answer

step-by-step explanation: