Question

If x = 1 and y = 2 is a solution of the pair of linear equations 2x − 3y + a = 0 and 2x + 3y − b = 0, then ______.

Options

• a = 2b

• 2a = b

• a + 2b = 0

• 2a + b = 0

Answer 1

If x = 1 and y = 2 is a solution of the pair of linear equations 2x − 3y + a = 0 and 2x + 3y − b = 0, then 2a = b.

Explanation:

Substituting x = 1, y = 2 in the given equations:

2(1) − 3(2) + a = 0 ⇒ a = 4

2(1) + 3(2) − b = 0 ⇒ b = 8

From these values, 2a = 2(4) = 8 = b