i. 2x + y = 5 …(i) 

3x – y = 5 …(ii) 

Adding equations (i) and (ii), 

2x + y = 5 + 3x – y = 5 

5x = 10 

∴ x = 10/5 

∴ x = 2 

Substituting x = 2 in equation (i), 

2(2) + y = 5 

4 + y = 5 

∴ y = 5 – 4 = 1 

∴ (2, 1) is the solution of the given equations.

ii. x – 2y = -1 

∴ x = 2y – 1 … .(i) 

∴ 2x – y = 7 ….(ii) 

Substituting x = 2y – 1 in equation (ii), 

2(2y – 1) – y = 7 

∴ 4y – 2 – y = 7 

∴ 3y = 7 + 2 

∴ 3y = 9 

∴ y = 9/3 

∴ y = 3 

Substituting y = 3 in equation (i), 

x = 2y – 1 

∴ x = 2(3) – 1 

∴ x = 6 – 1 = 5 

∴ (5, 3) is the solution of the given equations.

iii. x + y = 11 

∴ x = 11 – y …(i) 

2x – 3y = 7 …….(ii) 

Substituting x = 11 - y in equation (ii),

2(11 – y) – 3y = 7 

∴ 22 – 2y – 3y = 1 

∴ 22 – 5y = 7 

∴ 22 – 7 = 5y 

∴ 15 = 5y 

∴ y = 15/5 

∴ y = 3 

Substituting y = 3 in equation (i), 

x = 11 – y 

∴ x = 11 – 3 = 8 

∴ (8, 3) is the solution of the given equations.

iv. 2x + y = -2 …(i) 

3x – y = 7 …(ii) 

Adding equations (i) and (ii), 

2x + y = -2 + 3x – y = l 

5x = 5 

∴ x = 5/5

∴ x = 1 

Substituting x = 1 in equation (i), 

2x + y = -2 

∴ 2(1) + y = -2 

2 + y = -2 

∴ y = – 2 – 2 

∴ y = -4 

∴ (1, -4) is the solution of the given equations.

v. 2x – y = 5 

∴ -y = 5 – 2x 

∴ y = 2x – 5 …(i) 

3x + 2y = 11 ……(ii) 

Substituting y = 2x – 5 in equation (ii), 

3x + 2(2x – 5) = 11 

∴ 3x + 4x - 10 = 11 

∴ 7x = 11 + 10 

∴ 7x = 21 

∴ x = 21/7

∴ x = 3

Substituting x = 3 in equation (i), 

y = 2x – 5 

∴ y = 2(3) – 5 

∴ y = 6 – 5 = 1 

∴ (3,1) is the solution of the given equations.

vi. x – 2y = -2 

∴ x = 2y – 2 …(i) 

x + 2y = 10 …..(ii) 

Substituting x = 2y – 2 in equation (ii), 

2y – 2 + 2y = 10 

∴ 4y = 10 + 2 

∴ 4y = 12 

∴ y = 12/4

∴ y = 3 

Substituting y = 3 in equation (i), 

x = 2y – 2 

∴ x = 2(3) – 2 

∴ x = 6 – 2 = 4

∴ (4, 3) is the solution of the given equations.