Which of the following equation has 2 as a root?
If 2 is a root then substituting the value 2 in place of x should satisfy the equation.
A. Given, x2 - 4x + 5 = 0
⇒ (2)2 - 4(2) + 5 = 1 ≠ 0
So, x = 2 is not a root of x2 - 4x + 5 = 0
B. Given, x2 + 3x – 12 = 0
⇒ (2)2 + 3(2) – 12 = -2 ≠ 0
So, x = 2 is not a root of x2 + 3x – 12 = 0
C. Given, 2x2 - 7x + 6 = 0
⇒ 2(2)2 - 7(2) + 6 = 0
Here, x = 2 is a root of 2x2 - 7x + 6 = 0
D. Given, 3x2 - 6x – 2 = 0
⇒ 3(2)2 - 6(2) – 2 = -2 ≠ 0
So, x = 2 is not a root of 3x2 - 6x – 2 = 0