Sign In
Can you manipulate the coefficients of any variable terms such that they could be eliminated?
(4,-1,2)
The given system consists of equations of planes. Notice that the coefficient of y in the first equation is the additive inverse of the coefficient of y in the third equation; they will add to be 0. Let's use the Elimination Method to find a solution to this system. x - 2y+3z=12 & (I) 2x-y-2z=5 & (II) 2x + 2y-z=4 & (III) We can start by adding the third equation to the first equation to eliminate the z-terms.
(I): Add (III)
(I): Remove parentheses
(I): Add and subtract terms
Having eliminated the y-variable from the first equation, we can continue by creating additive inverse coefficients for y in the second and third equations. Then, we can add or subtract these equations to eliminate y from the second equation.
(II): LHS * 2=RHS* 2
(II): Add (III)
(II): Remove parentheses
(II): Add and subtract terms
(I): LHS * 5=RHS* 5
(II):LHS * 2=RHS* 2
(II): Add (I)
(II): Remove parentheses
(II): Add terms
(II): .LHS /27.=.RHS /27.
Now that we know that x=4, we can substitute it into the first equation to find the value of z.
The value of z is 2. Let's substitute both values into the third equation to find y.
The solution to the system is ( 4, -1, 2). 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
(II): a-(- b)=a+b
(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.