Question

$x=2$, $y=-1$is a solution of the linear equation:

• A. $x+2y=0$
• B. $x+2y=4$
• C. $2x+y=0$
• D. $2x+y=2$

Answer 1

The correct option is A

$x+2y=0$

Explanation of the correct option:

Option (A): $x+2y=0$

$x=2$ $\&y=(-1)$ is the solution of the linear equation.

In equation $x+2y=0$

Taking, $LHS=2x+y$ and putting the values $x=2$ $\&y=(-1)$, we get;

$2+2\times (-1)$

$\Rightarrow 2-2=0$

$\Rightarrow 0=RHS$

Since, $LHS=RHS$, $x=2$ $\&y=(-1)$ is the solution of the linear equation $x+2y=0$.

Explanation of the incorrect option:

Option (B) $x+2y=4$

Taking, $LHS=x+2y$ and putting the values $x=2$ $\&y=(-1)$, we get;

$2+2\times (-1)$

$\Rightarrow 2-2=0$

$\Rightarrow 0\ne RHS$

Since, $LHS\ne RHS$, $x=2$ $\&y=(-1)$ is not a solution of the linear equation

Option (C) $2x+y=0$

Taking, $LHS=2x+y$ and putting the values $x=2$ $\&y=(-1)$, we get;

$2\times 2-1$

$\Rightarrow 4-1$

$\Rightarrow 3\ne RHS$

Since, $LHS\ne RHS$, $x=2$ $\&$ $y=(-1)$ is not a solution of the linear equation

Option (D) $2x+y=2$

$LHS=2x+y$ and putting the values $x=2$ $\&y=(-1)$, we get;

$2\times 2+(-1)$

$\Rightarrow 4-1$

$\Rightarrow 3\ne RHS$

Since, $LHS\ne RHS$, $x=2$ $\&$ $y=(-1)$ is not a solution of the linear equation.