The solution of the system of equations $\dfrac{4}{x} + 5y = 7 \text{ and } \dfrac{3}{x} + 4y = 5$ is

1. $x = \dfrac{1}{3}, y = -1$

2. $x = -\dfrac{1}{3}, y = 1$

3. x = 3, y = -1

4. x = -3, y = 1

A pair of linear equations which has a unique solution x = 2, y = -3 is

1. x + y = -1
   2x - 3y = -5

2. 2x + 5y = -11
   4x + 10y = -22

3. 2x - y = 1
   3x + 2y = 0

4. x - 4y - 14 = 0
   5x - y - 13 = 0

Assertion (A): A solution of x - y = 1, 2x + y = $\dfrac{7}{2}$ is x = $\dfrac{3}{2}$, y = $\dfrac{1}{2}$.

Reason (R): One of the methods of solving a pair of linear equations is elimination method.

1. Assertion (A) is true, Reason (R) is false.

2. Assertion (A) is false, Reason (R) is true.

3. Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct reason for Assertion (A).

4. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct reason (or explanation) for Assertion (A).

Assertion (A): Solving $\sqrt{2}x - \sqrt{3}y$ = 0, $\sqrt{3}x + \sqrt{2}y$ = 5 yields x = $\sqrt{3}$, y = $\sqrt{2}$.

Reason (R): We can use cross-multiplication method to solve a pair of linear equations.

1. Assertion (A) is true, Reason (R) is false.

2. Assertion (A) is false, Reason (R) is true.

3. Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct reason for Assertion (A).

4. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct reason (or explanation) for Assertion (A).