Pearson Algebra 2 Common Core, 2011
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Pearson Algebra 2 Common Core, 2011 View details
5. Systems With Three Variables
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Exercise 33 Page 172

Can you manipulate the coefficients of any variable terms such that they could be eliminated?

Practice makes perfect
The given system consists of equations of planes. Notice that the coefficient of in the first equation is the additive inverse of the coefficient of in the second equation; they will add to be Therefore, let's use the Elimination Method to find a solution to this system.
We can start by adding the second equation to the first equation to eliminate the
Having eliminated the variable from the first equation, we can continue by creating additive inverse coefficients for in the second and third equations. Then, we can add or subtract these equations to eliminate from the second equation.
Simplify
Next, we will use our two equations that are only in terms of and to solve for the value of one of the variables. We will once again apply the Elimination Method, but this time it will be similar to when using it in a system with only two variables.
Solve by elimination
Now that we know that we can substitute it into the first equation to find the value of
Solve for
The value of is Let's substitute both values into the third equation to find
Solve for
The solution to the system is This is the singular point at which all three planes intersect.