Answer: the individual cost of Tanya's items is $9
the individual cost of Tony's items is $6.75
Step-by-step explanation:
Let x represent the individual cost of Tanya's items.
Let y represent the individual cost of Tony's items.
Each of the items that Tony bought was $2.25 less than the items Tanya bought. It means that
x = y + 2.25
Tanya bought 3 items that each cost the same amount. Tony bought 4 items that each cost the same amount. Both Tanya and Tony paid the same amount of money. It means that
3x = 4y- - - - - - - - - -1
Substituting x = y + 2.25 into equation 1, it becomes
3(y + 2.25) = 4y
3y + 6.75 = 4y
4y - 3y = 6.75
y = 6.75
x = y + 2.25 = 6.75 + 2.25
x = 9