Linear equations in two variables class 9 CBSE

Linear equations in two variables class 9 CBSE

1. Linear equations in two variables
Class-9
Done by: Smrithi Jaya

2. Linear equations in two variables
•The general form of linear equations in two
variables is where �, �
and � are integers

•For example: we have 5 chocolates in right
hand and another 5 chocolates in left hand
•So,
5+5=10
5+5−10=0
��+��+�=??????

3. Some Basic Formulas
•A linear equation in two variables can have
infinitely many solutions
•In a linear equation if the constant term is
zero, then the line will pass through the origin
or we can say that �=??????� is a line which
passes through the origin
•The Celsius – Fahrenheit equation
(f=farenheit ,c=celcius)

??????=
9
5
??????+32

4. EXAMPLES :

Write in the form of
��+ �� + � = 0 ,
and indicate a, b, c in
each case

5. Write in 2 variables

6. Find solutions for linear equation

7. Find solutions for linear equation

11. Write Linear equation in two variables
a) Tana’s age exceeds Vishnu’s age by 6 years
let the age of Tana be x and let the age of
Vishnu be y
� − � = 6
� = 6 + �
� = �+ 6

Important words : ‘’is’’ can mean ‘’=‘’
‘’and ‘’ can mean ‘’sum’’

12. Write Linear equation in two variables
b)Sum of 2 friends marks is 10
Let marks be � and �
� + �=10

c) Cost of a pen and a pencil is Rs. 25
Let cost of the pen be � and Let cost of the
pencil be �
�+�=25

13. Write Linear equation in two variables
d) cost of notebook is twice the cost of the pen
Let the cost of notebook be � and cost of pen be �
??????=2�

e) The ordinate is thrice the abscissa
let ordinate be � and abscissa be �
�=3�