How do you solve this Math problem? (Simultaneous equation)

One packet of bsicuit costs $x and 1 cup of ice-cream cost $y.
One packet of biscuits and 2 cups of ice-cream cost $8.00, while a packet of biscuits and one cup of ice-cram cost $9.60.

(i) Write a pair of simultaneous equations in x and y to represent the given information.
Then solve the equation above.

x + 2y = $8.00 (1)
x + y = $9.60 (2)

Subtract (2) from (1)

y = -$1.60 x = $11.20

or did you write it incorrectly?