The cost of a notebook is twice the cost of a pen. Write a linear equation in two variables to represent this statement.

(Take the cost of a notebook to be ₹ x and that of a pen to be ₹ y).

Express the following linear equations in the form ax + by + c = 0 and indicate the values of a, b and c in each case :

-2x + 3y = 6

Express the following linear equations in the form ax + by + c = 0 and indicate the values of a, b and c in each case :

x = 3y