Answer :

Building systems of equations, we have that:

a) The price of a cow is of 1200 coins, the price of a sheep is of 500 coins and the price of a pig is of 300 coins.

b) The system of equations is composed by the equations given below.

  • x + 9 + 4 = 15.
  • 7 + y + z = 15.
  • t + 1 + w = 15.
  • x + 7 + t = 15.
  • 9 + y + 1 = 15.
  • 4 + z + w = 15.
  • x + y + w = 15.
  • 4 + y + t = 15.

What is a system of equations?

A system of equations is when two or more variables are related, and equations are built to find the values of each variable.

For item a, the variables are given as follows:

  • Variable x: Price of a cow.
  • Variable y: Price of a sheep.
  • Variable z: Price of a pig.

Considering that a sell is positive money and a buy negative, and the text, the equations are given as follows:

  • 2x + 5y - 13z = 1000.
  • 3x - 9y + 3z = 0.
  • -5x + 6y + 8z = -600.

Using a calculator, the solutions are given as follows:

x = 1200, y = 500, z = 300.

Hence:

The price of a cow is of 1200 coins, the price of a sheep is of 500 coins and the price of a pig is of 300 coins.

For item b, all missing values are variables, given by:

x, y, z, t and w.

From the sum of the rows:

  • x + 9 + 4 = 15.
  • 7 + y + z = 15.
  • t + 1 + w = 15.

From the sum of the columns:

  • x + 7 + t = 15.
  • 9 + y + 1 = 15.
  • 4 + z + w = 15.

From the diagonals:

  • x + y + w = 15.
  • 4 + y + t = 15.

The system is composed by all these equations.

More can be learned about a system of equations at https://brainly.com/question/24342899

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