Class 9 Maths NCERT Solution for Linear equation part 1

In this page we have NCERT book Solutions for Class 9th Maths:Linear equation for EXERCISE 1 . Hope you like them and do not forget to like , social share and comment at the end of the page.

Question1:

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.)

Solution:

Let cost of notebook and a pen be x and y respectively.

Cost of note book = 2  cost of pen

x = 2y

x - 2 y = 0

Question 2:

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=9.3555555555…

(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

Solution:

( i) 2x+3y=9.3555555555….

=> 2x+3y-9.3555555555…. =0

Comparing this equation with ax + by + c = 0,

a=2 ,b=3  c=-9.355….

(ii)  x-(y/5)-10=0

Comparing this equation with ax + by + c = 0,

a = 1, b =, -1/5, c = −10

(iii) − 2x + 3 y = 6

=> − 2x + 3 y − 6 = 0

Comparing this equation with ax + by + c = 0,

a = −2, b = 3, c = −6

(iv)       x = 3y

=> x − 3y + 0 = 0

Comparing this equation with ax + by + c = 0,

a = 1, b = −3, c = 0

(v) 2x = −5y

=> 2x + 5y + 0 = 0

Comparing this equation with ax + by + c = 0,

a = 2, b = 5, c = 0

(vi) 3x + 2 = 0

=> 3x + 0.y + 2 = 0

Comparing this equation with ax + by + c = 0,

a = 3, b = 0, c = 2

(vii) y − 2 = 0

=> y − 2 = 0

Comparing this equation with ax + by + c = 0,

a = 0, b = 1, c = −2

(vii) 5 = 2x

=> − 2x  + 5 = 0

Comparing this equation with ax + by + c = 0,

a = −2, b = 0, c = 5