Question

4. Which of the following equations has not 2 as a root?
(a) x² - 4x + 5 =0
(b) x² + 3x – 12 = 0
(c) 2x² – 7x+6=0
(d) 3x² - 6x - 2 = 0​

Answer 1

a ,b and d hasn't 2 as root

Answer 2

The equations a) , b) and d) don't have 2 as their root.

For a equation to have a number as it's root the number must satisfy the equation.

For equation a) -

=> (2)² - 4×2 +5 = 1 , 2 is not a root as 2 doesn't satisfy the equation.

For equation b) -

=> (2)² + 3×2 -12 = -2 , 2 is not a root as 2 doesn't satisfy the equation.

For equation c) -

=> 2(2)² - 7×2 +6 = 0 , 2 is a root as 2 satisfies the equation.

For equation d) -

=> 3(2)² - 6×2 -2= -2 , 2 is not a root as 2 doesn't satisfy the equation.