Please solve and explain how you did it.

Question

Mary and Jennifer had an equal number of crackers. Each day, Mary ate 12 crackers and Jennifer ate 6 more crackers than Mary. When Jennifer had 24 crackers left, Mary had 96 crackers left. How many crackers did each of them have at first?

Answer 1

let x=amount of crackers each had

ley y=# of days eating crackers

Mary: x-12y=96

Jennifer: x-18y=24

x-12y=96

x-18y=24

subtract the equations

6y=72

y=12 days of eating crackers

x-12*12=96 and x-18*12=24

x-144=96

x=144+96

x=240 crackers, or...

x-216=24

x=216+24

x=240 crackers