Linear Equations In Two Variables
Q1: 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 Rs x and that of a pen to be Rs y.)
Let the cost of a notebook and a pen be x and y respectively.
Cost of notebook = 2 ☓ Cost of pen
x = 2y
x − 2y = 0
Q2: Express the following linear equations in the form ax + by + c = 0 and indicate the values of a, b, c in each case:
(i) 2x + 3y = 9.35
(ii) x - y/5 - 10 = 0
(iii) − 2x + 3 y = 6
(iv) x = 3y
(v) 2x = − 5y
(vi) 3x + 2 = 0
(vii) y − 2 = 0
(viii) 5 = 2x