Solve by elimination method

Question 1

Solve the following simultaneous linear equations

x + y = 2 (1)

2x + y = 3 (2)

Answer 1

Subtract (2) by 1 2x - x = 3 - 2

Find x x = 1

Substitute into (1) 1 + y = 1

Find y y = 1 - 1

= 0

Question 2

Solve the following simultaneous linear equations

x + y = 3 (1)

2x - y = 3 (2)

Answer 2

Add (2) to (1) 2x + x = 3 + 3

Find x 3x = 6

x = 2

Substitute into (1) 2 + y = 3

Find y y = 3 - 2

= 1

Question 3

Solve the following simultaneous linear equations

2x + y = 3 (1)

3x - 2y = 1 (2)

Answer 3

Mutiply (1) by 2 4x + 2y = 6 (3)

Add (3) to (2) 4x + 3x = 6 + 1

Find x 7x = 7

x = 1

Substitute into (1) 2 + y = 3

Find y y = 3 - 2

= 1