Astudent got a summer job at an electronics store. the student is given two different compensation plans. plan a pays a weekly salary $250 plus commission of $25 for each phone sold. plan b offers no salary but pays $50 commission on each cellphone sold. how many cellphones will the student have to sell to make the same amount of money on both plans? when is plan b a better plan? when is plan a the better plan? solve using "system of equations"