Which system of linear equations has the ordered pair (-2,8) as its solution?
Oy - 2x = 12 and x - 2y = -18
O x – 2y = 12 and y - 2x = -18
Oy + 2x = 12 and x + 2y = -18
O x + 2y = 12 and y + 2x = -18

Respuesta :

Answer:

The solution to the system of linear equations is:

(x, y) = (-2, 8)

Hence, y - 2x = 12 and x - 2y = -18  has the ordered pair (-2,8) as its solution. Thus, option A is correct.

Step-by-step explanation:

Checking the first system of equations

y - 2x = 12

x - 2y = -18

solving the first system of equations

[tex]\begin{bmatrix}y-2x=12\\ x-2y=-18\end{bmatrix}[/tex]

[tex]\mathrm{Multiply\:}y-2x=12\mathrm{\:by\:}2\:\mathrm{:}\:\quad \:2y-4x=24[/tex]

[tex]\begin{bmatrix}2y-4x=24\\ -2y+x=-18\end{bmatrix}[/tex]

adding the equations

[tex]-2y+x=-18[/tex]

[tex]+[/tex]

[tex]\underline{2y-4x=24}[/tex]

[tex]-3x=6[/tex]

[tex]\begin{bmatrix}2y-4x=24\\ -3x=6\end{bmatrix}[/tex]

solving -3x=6 for x

[tex]-3x=6[/tex]

Divide both sides by -3

[tex]\frac{-3x}{-3}=\frac{6}{-3}[/tex]

Simplify

[tex]x=-2[/tex]

[tex]\mathrm{For\:}2y-4x=24\mathrm{\:plug\:in\:}x=-2[/tex]

[tex]2y-4\left(-2\right)=24[/tex]

[tex]2y+8=24[/tex]

Subtract 8 from both sides

[tex]2y+8-8=24-8[/tex]

Simplify

[tex]2y=16[/tex]

Divide both sides by 2

[tex]\frac{2y}{2}=\frac{16}{2}[/tex]

Simplify

[tex]y=8[/tex]

Therefore, the solution to the system of linear equations is:

(x, y) = (-2, 8)

Hence, y - 2x = 12 and x - 2y = -18  has the ordered pair (-2,8) as its solution. Thus, option A is correct.