Can you help me please?​

Carter drank 15.75 gallons of water in 4 weeks. he drank the same amount of water each day. a. estimate how many gallons he drank in one day. b. estimate how many gallons he drank in one week. c. about how many days altogether will it take him to drink 20 gallons?

Which value of m will create a system of parallel lines with no solution? y = mx - 6 8x - 4y = 12

How are algebraic expressions evaluated using substitution?