Need help with question 3. Anything helps:) I don’t understand

Cost of each package:          

Hot dog = $3.25

Buns = $2.75

Hamburgers = x         (x = the cost of each hamburger package)

Tony bought 3 packages of hot dogs, 3 packages of hamburgers, and 5 packages of buns for a total cost of $37.75. So:

Cost of hot dog = 3(3.25)      [3 hot dog packages for $3.25 each]

Cost of bun = 5(2.75)        [5 bun packages for $2.75 each]

Cost of hamburger = 3x      [3 hamburger packages for x dollars each]

Cost of hamburger + Cost of hot dog + Cost of bun = total cost

3x + 3(3.25) + 5(2.75) = 37.75    

Your answer is A and D, because for A you distribute 3 into (x + 3.25), which will be (3)x + (3)3.25.