CBSE Notes, Lectures

CBSE - Mathematics - Pair of Linear Equations in Two Variables

Pair of Linear Equations in Two Variables

NCERT Exercise Exercise 3.4

2. Form the pair of linear equations in the following problems, and find their solutions (if they exist) by the elimination method:

(i) If we add 1 to the numerator and subtract 1 from the denominator, a fraction reduces to 1. It becomes 1/2 if we only add 1 to the denominator. What is the fraction?

(i) Let the fraction be x/y
According to the question,x + 1/y - 1 = 1
⇒ = -2 ... (i)x/y+1 = 1/2
⇒ 2x - = 1 ... (ii)
Subtracting equation (i) from equation (ii), we get
x = 3 ... (iii)
Putting this value in equation (i), we get
3 - y = -2
-y = -5
y = 5
Hence, the fraction is 3/5

.