Sagot :
[tex]-2x-y=1 \ \ \ \ | \cdot (-2)\\
-4x-2y=1 \\ \\
4x+2y=-2 \\
\underline{-4x-2y=1 \ \ \ } \\
4x-4x+2y-2y=1-2 \\
0=-1 \\
[/tex]
This system has no solutions.
This system has no solutions.
Equation system:
[tex]-2x-y=1-3x-2y \\ -2x+3x-y+2y=1-3x+3x-2y+2y=x+y=1[/tex]
Subsitute x with 1-y and solve y:
[tex]1-4(1-y)-2y=1 \\ 1-4+4y-2y=1 \\ 2y=4 \\ y=2[/tex]
Put the answer into the equation:
[tex]-2x-2=1 \\ x=1.5[/tex]
[tex]-2x-y=1-3x-2y \\ -2x+3x-y+2y=1-3x+3x-2y+2y=x+y=1[/tex]
Subsitute x with 1-y and solve y:
[tex]1-4(1-y)-2y=1 \\ 1-4+4y-2y=1 \\ 2y=4 \\ y=2[/tex]
Put the answer into the equation:
[tex]-2x-2=1 \\ x=1.5[/tex]