Actually post 17 status updates on her Facebook wall each day. Roberto posts 21 status updates on his Facebook wall each day. Part A: define each variable and write an algebraic expression to describe the combined number of posts for Ashley and Roberto after any given number of days. part b: write an algebraic expression to describe the difference between number of posts for Ashley and Roberto after any given number of days.

No. of status posted by Ashley each day = 17

No. of status posted by Roberto each day = 21

An algebraic expression to describe the combined number of posts for Ashley and Roberto after any given number of days can be written as

17x+21y

An algebraic expression to describe the difference between number of posts for Ashley and Roberto after any given number of days can be written as

17x - 21y

Here in above equations, x and y represents the numbers of days for Ashley and Roberto.