The answer would be d , because you have to add how many of each fish to equal up to the sum of 420 . which is x y . so the first equation is x + y = 420 . then it says he bought 6 times as many parrotfish as he did angelfish so you would have to multiply x which represents angelfish by 6 . to get the second equation of y = 6x .
X = how much Tim has
y = how much Tom has
x + y = 2.40
x = 3y
Substitute 3y for x
3y + y = 2.40
4y = 2.40
y = 0.60
Plug in y value into previous equation
x = 3(0.60)
x = 1.80
ANSWERS: Tim has $1.80 and Tom has $0.60