Please help 1-9 {30 points + brainlist}

What is the first step of an indirect proof of a number that is divisible by two

Which recursive formula can be used to determine the total amount of money earned in any year based on the amount earned in the previous year? f(n+1)=f(n)+5

Jada has a monthly budget for her cell phone bill. last month she spent 120% of her budget, and the bill was 60$. what is jada’s monthly budget