Write the following equation in the standard form $ax + by + c = 0$ and indicate the values of $a, b,$ and $c$ in each case:
$0.2x + 0.5y = 1.2$

Write $5 x-3 y=15$ in the standard form of a linear equation in two variables.

Write four solutions for the equation $3x - 24 = 0$.

If $(3, 2)$ is one of the solutions of $5x - ay = 7$,then $a = \dots$

The work done by a body on application of a constant force is the product of the constant force and the distance travelled by the body in the direction of force. Express this in the form of a linear equation in two variables and draw its graph by taking the constant force as $3$ units. What is the work done when the distance travelled is $2$ units? Verify it by plotting the graph.

If $(-2, -3)$ is a solution of the equation $ax - 5y = 21$,then $a = \ldots$