Question

The total cost of 4 goldfish and 3 guppies is $29. 3 goldfish and 5 guppoes cost $30. How much does each cost

Answer 1

let the goldfish be x and the guppies be y

4x + 3y = 29...equ(1)

3x + 5y = 30...equ(2)

multiplying equation 1 by 5 and equation 2 by 3

20x + 15y = 145...equ(1)

9x + 15y = 90...equ(2)

subtracting equation 2 from 1

11x = 55

∴x = 5

 substituting the value of x into equation

4(5) + 3y = 29

20 + 3y = 29

3y = 9

∴y =3