Solve the system of equations by finding the reduced row-echelon form of the augmented matrix for the system of equations.
2x + 2y + 4z = 16
5x-2y+3z= -1
x+2y-3z=-9

Respuesta :

Answer:

the answer is C:  ( -1,2,4)

Step-by-step explanation:

I CHOSE IT AND GOT IT RIGHT

The solution of given system of equations is [tex]\bold{x=\frac{-5}{3},~y=\frac{43}{21},~z=\frac{80}{21}}[/tex]

What is system of equations?

"It is a finite set of equations for which we find the common solution."

What is row-echelon form?

"It is a simplified equivalent version of a matrix which has been reduced row by row."

What is reduced row-echelon form?

"It is a type of matrix used to solve systems of linear equations."

What is augmented matrix for system of equations?

"It is a matrix of numbers in which each row represents the constants from one equation and each column represents all the coefficients for a single variable."

For given question,

we have been given a system of equations

2x + 2y + 4z = 16

5x - 2y + 3z = -1

x + 2y - 3z = -9

The augmented matrix for above system of equations would be,

[tex]\begin{bmatrix}2 & 2 & 4 & 16 \\5 & -2 & 3 & -1 \\1 & 2 & -3 & -9\end{bmatrix}[/tex]

Now, we find the reduced row-echelon form of the augmented matrix.

[tex]=\begin{bmatrix}2 & 2 & 4 & 16 \\5 & -2 & 3 & -1 \\1 & 2 & -3 & -9\end{bmatrix}\\\\\\=\begin{bmatrix}2 & 2 & 4 & 16 \\0 & -7 & -7 & -41 \\1 & 2 & -3 & -9\end{bmatrix} ~~~~~~~~~.................(R2\rightarrow R2-\frac{5}{2} R1)\\\\\\=\begin{bmatrix}2 & 2 & 4 & 16 \\0 & -7 & -7 & -41 \\0 & 1 & -5 & -17\end{bmatrix}~~~~~~~~~...................(R3\rightarrow R3-\frac{1}{2} R1)[/tex]

[tex]=\begin{bmatrix}2 & 2 & 4 & 16 \\0 & -7 & -7 & -41 \\0 & 0 & -6 & \frac{-160}{7}\end{bmatrix}~~~~~~~~......................(R3\rightarrow R3-(\frac{-1}{7} )R2)[/tex]

So, we get system of equations,

[tex](2\times x) +(2\times y) +(4\times z) = 16 \\\\(-7\times y) -(7\times z) = -41 \\\\(-6\times z) = \frac{-160}{7}[/tex]

After solving above system of equations we have,

[tex]x=\frac{-5}{3},~y=\frac{43}{21},~z=\frac{80}{21}[/tex]

Therefore, the solution of given system of equations is,

[tex]\bold{x=\frac{-5}{3},~y=\frac{43}{21},~z=\frac{80}{21}}[/tex]

Learn more about system of equations here:

https://brainly.com/question/12895249

#SPJ2