If the graph of equation $a x+3 y=21$ passes through the point $(5,2)$ then the value of $a=\ldots \ldots \ldots$

Express the following linear equation in the form $a x+b y+c=0$ and indicate the values of $a, b$ and $c$ in each case

$2 y-3 x=14$

At what point does the graph of the linear equation $x+y=5$ meet a line which is parallel to the $y$ -axis, at a distance $2$ units from the origin and in the positive direction of $x$ – axis.

The force exerted to pull a cart is directly proportional to the acceleration produced in the body. Express the statement as a linear equation of two variables and draw the graph of the same by taking the constant mass equal to $6 \,kg .$ Read from the graph, the force required when the acceleration produced is $(i)$ $5\, m / sec ^{2}$, $(ii)$ $6 \,m / sec ^{2}$

Write four solutions for each of the following equations

$3 x+5 y=0$