Q. 1 E3.9( 16 Votes )

# Solve each of the following pairs of equations by reducing them to a pair of linear equation.

and

Let = p and = q

5p – 2q = -1 ….I

15p + 7q = 10 ….II

Multiply Eq. I by 3 and subtract eq. II

15p – 6q = -3

-15p - 7q = -10

-13q = -13

q = 1

substitute the value of q in Eq. I

5p – 2(1) = -1

5p = - 1 + 2

5p = 1

p =

But, 5 = x + y …III

1 = x – y y = x – 1

Substitute value of y in eq. III

x + x – 1 = 5

2x = 6

x = 3

y = 3 – 1 = 2

x = 3 and y = 2

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