Agym membership costs $40 per month plus a one time sign up fee of $20. how many months would it take to spend $1000 for the gym membership?

Last month, a 770 g box of cereal was sold at a grocery store for $3.10. however, this month, the cereal manufacturer launched the same cereal in a 640 g box, which is being sold at $2.50. what is the percent change in the unit price?

How do i multiply two digit numbers

What is r i 4.5+10r=-6.5 with work pls