Does anyone know how to find the common difference of the arithmetic sequence? if you do can someone help me!

Find the common difference of the arithmetic sequence -9, -7, -5,

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

Jim had 3,067.48 in his checking account he wrote a check to pay for two airplane tickets. his account now has 1,845.24.

The water company charges a residential customer $41 for the first 3,000 gallons of water used and $1 for every 200 gallons used over 3000 gallons. if the water bill was $58 how many gallons of water were usedanswersa 3400 gallonsb 6000 gallonsc 6400 gallons d 7000 gallons