"The price of a bat in a toy store is five times the price of a ball." Represent this statement as a linear equation in two variables.

If the point $(5, 2)$ lies on the graph of the equation $3x + 2y = k$,then $k = \ldots$

Write four solutions for the following equation: $2x + 5y = 20$.

The autorickshaw fare in a city is charged $Rs. 10$ for the first kilometer and $Rs. 4$ per kilometer for the subsequent distance covered. Write the linear equation to express the above statement and draw the graph of the linear equation.

If the point $(2, 3)$ lies on the graph of the equation $3x + ay = 18$,find the value of $a$.

The point of the form $(a, a)$ always lies on: