Question

Find the value of $k$ if $x=4;y=-2$ is a solution of the equation $5x+4y=k$

Answer 1

Given that, $x=4,y=-2$ is a solution of the equation $5x+4y=k$

To find out: The value of $k$.

On substituting the values of $x$ and $y$ in the equation, the LHS and RHS should be equal.

$\therefore 5\left(4\right)+4(-2)=k$

$\Rightarrow 20-8=k$

$\therefore k=12$

Hence, if $x=4,y=-2$ is a solution of the equation $5x+4y=k$, then the value of $k$ is $12$.