Answer: A single turquoise guppy costs $3.69
Step-by-step explanation:
Let us use "x" to represent the amount a single turquoise is sold and use "y" to represent that of the Glo fish.
Since Kellen bought 4 guppies and 3 glo fishes for $41.73:
4x + 3y = 41.73 --------eqn 1
Similarly, Danielle purchased 3 guppies and 5 Glo fish for $56.02:
Therefore 3x + 5y = $56.02 -----eqn2
The 2 equations are;
4x + 3y = 41.73 (eqn 1)
3x + 5y = 56.02 (eqn 2)
We then solve the simultaneous equations using substitution method:
From eqn 1,
4x + 3y = 41.73
4x = 41.73 - 3y
x = (41.73 - 3y)/4
Substitute x for (41.73 - 3y)/4 in eqn2.
3[(41.73 - 3y)/4 + 5y = 56.02
11y + 125.19 = 224.08
11y =98.89
y = 98.89/11
y = $8.99
So, 1 Glo fish costs $8.99
Then, substitute "y" for 8.99 in equation 1
4x + (3×8.99) = 41.73
4x + 26.97 = 41.73
4x = 41.73 - 26.97
4x = 14.76
x = 14.76/4
x = $3.69
Therefore 1 turquoise guppy costs $3.69
