Respuesta :
Using a system of equations, it is found that:
- Each pound of strawberry cost $3.
- Each pound of grape cost $1.25.
- Each pound of melon costs $4.75.
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For our system, we have that:
- x is the cost of a pound of strawberry.
- y is the cost of a pound of grape.
- z is the cost of a pound of melon.
Three pounds of strawberries, five pounds of grapes, and one pound of melon at a cost of $20.
This means that:
[tex]3x + 5y + z = 20[/tex]
[tex]z = 20 - 3x - 5y[/tex]
Three pounds of strawberries, two pounds of grapes, and two pounds of melon at a cost of $21.
This means that:
[tex]3x + 2y + 2z = 21[/tex]
[tex]3x + 2y + 2(20 - 3x - 5y) = 21[/tex]
[tex]3x + 2y + 40 - 6x - 10y = 21[/tex]
[tex]3x + 8y = 19[/tex]
Four pounds of strawberries, three pounds of grapes, and three pounds of melon at a cost of $30.
This means that:
[tex]4x + 3y + 3z = 30[/tex]
[tex]4x + 3y + 3(20 - 3x - 5y) = 30[/tex]
[tex]4x + 3y + 60 - 9x - 15y = 30[/tex]
[tex]5x + 12y = 30[/tex]
For x and y, the system is:
[tex]3x + 8y = 19[/tex]
[tex]5x + 12y = 30[/tex]
Multiplying by 5 and -3, we get:
[tex]15x + 40y = 95[/tex]
[tex]-15x - 36y = -90[/tex]
Then, adding them:
[tex]4y = 5[/tex]
[tex]y = \frac{5}{4}[/tex]
[tex]y = 1.25[/tex]
Each pound of grape cost $1.25.
Solving for x:
[tex]5x + 12y = 30[/tex]
[tex]5x + 12(1.25) = 30[/tex]
[tex]5x = 15[/tex]
[tex]x = \frac{15}{5}[/tex]
[tex]x = 3[/tex]
Each pound of strawberry cost $3.
Finally, for z:
[tex]z = 20 - 3x - 5y[/tex]
[tex]z = 20 - 3(3) - 5(1.25)[/tex]
[tex]z = 4.75[/tex]
Each pound of melon costs $4.75.
A similar problem is given at https://brainly.com/question/17096268