Pearson Algebra 2 Common Core, 2011
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Pearson Algebra 2 Common Core, 2011 View details
6. Solving Systems Using Matrices
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Exercise 7 Page 179

Review how the matrix representations for systems of equations work.

See solution.

Practice makes perfect

Recall that when we represent a system of equations with a matrix, we use the coefficients of the variables and the constant terms as the matrix elements. This is how it works.

  • Each row represents an equation
  • The first column represents the x variable's coefficients
  • The second column represents the y variable's coefficients
  • The last column represents the constant terms.

    With this in mind, we can explicitly write the system of equations being represented by the matrix given in the exercise. A= [ cc|c 4 & 2 & 8 0 & 1 & 2 ] ⇒ 4x+ 2y= 8 & (I) 1* y= 2 & (II) Now we can think of a real-life situation we can model with this system. For example, x and y can represent the prices of different kind of candies — let's use bubble gum and chocolate bars, respectively.

    Mathematical expressions and equations. Verbal information
    x Price of a bubble gum
    y Price of a chocolate bar
    y=2 The price of a chocolate bar is $2.
    4x +2y=8 The total price for 4 bubble gums and 2 chocolate bars is $8.

    Notice that this is only an example, as this system could represent infinitely many different situations.