Answer: the price of a guppy is $3.19 and the price of a platy is $2.19
Step-by-step explanation:
Let x represent the price of a guppy.
Let y represent the price of a platy.
Marta brought 3 guppies and 2 platies for a total of $13.95. It means that
3x + 2y = 13.95 - - - - - - - - - - - 1
Hank also bought 3 guppies and 4 platies for a total of $18.33. It means that
3x + 4y = 18.33 - - - - - - - - - - - 2
Subtracting equation 2 from equation 1, it becomes
2y - 4y = 13.95 - 18.33
- 2y = - 4.38
y = - 4.38/ - 2
y = 2.19
Substituting y = 2.19 into equation 1, it becomes
3x + 2 × 2.19 = 13.95
3x + 4.38 = 13.95
3x = 13.95 - 4.38 = 9.57
x = 9.57/3 = 3.19
