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Can you manipulate the coefficients of any variable terms such that they could be eliminated?
(2,1,-5)
The given system consists of equations of planes. Notice that the coefficient of z in the first equation is the additive inverse of the coefficient of z in the second equation; they will add to be 0. Let's use the Elimination Method to find a solution to this system. -2x+y - z=2 & (I) - x-3y + z=-10 & (II) 3x+6z=-24 & (III) We can start by adding the second equation to the first equation to eliminate the z-terms.
(I): Add (II)
(I): Remove parentheses
(I): Add and subtract terms
Having eliminated the z-variable from the first equation, we can continue by creating additive inverse coefficients for z in the second and third equations. Then, we can add or subtract these equations to eliminate z from the third equation.
(II): LHS * (-6)=RHS* (-6)
(II): Add (III)
(II): Remove parentheses
(II): Add and subtract terms
(II):.LHS /9.=.RHS /9.
Next, we will use our two equations that are only in terms of x and y 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.
Now that we know that x=2, we can substitute it into the first equation to find the value of y and into the third equation to find z.
(I), (III): x= 2
(I), (III): Multiply
(I): LHS+6=RHS+6
(I): .LHS /(-2).=.RHS /(-2).
(III):LHS-6=RHS-6
(III):.LHS /6.=.RHS /6.
The solution to the system is ( 2, 1, -5). This is the singular point at which all three planes intersect. Now, we can check our solution by substituting the values into the system.
(I), (II), (III): Substitute values
(I), (II), (III): Multiply
(I), (II), (III): Add and subtract terms
Since the substitution of our answers into the given equations resulted in three identities, we know that our solution is correct.