Question

Which of the following points do not lie on the line 2x - y + 4 = 0?

• A. (1,6)
• B. (2,8)
• C. (4,10)
• D. (3,6)

Answer 1

The correct option is D (3,6)

A point lies on a line if its coordinates satisfy the equation of the line.
The equation of the line is 2x - y +4 = 0

To check if (1,6) lies on the line substitute x = 1, y = 6 in its equation.
LHS = 2(1) - 6 +4 = 0 = RHS
Therefore, (2,0) lies on the line 2x - y +4 = 0

To check if (2,8) lies on the line substitute x = 2, y = 8 in its equation.
LHS = 2(2) - 8 +4 = 0 = RHS
Therefore, (2,8) lies on the line 2x - y +4 = 0

To check if (4,10) lies on the line substitute x = 4, y = 10 in its equation.
LHS = 2(4) - 10 +4 = 0 = RHS
Therefore, (4,10) lies on the line 2x - y +4 = 0

To check if (3,6) lies on the line substitute x = 3, y = 6 in its equation.
LHS = 2(3) - 6 +4 = 4 and RHS = 0
4 $\ne$ 0 = Hence LHS $\ne$ RHS
Therefore, (3,6) does not lies on the line 2x - y +4 = 0