Which of the following equations has 2 as a root
a. x² - 4x + 5 = 0
b. x² + 3x - 12 = 0
c. 2x² - 7x + 6 = 0
d. 3x² - 6x - 2 = 0
Solution:
We have to find which equation has 2 as a root.
From the options,
A) x² - 4x + 5 = 0
Put x = 2
LHS: x² - 4x + 5
= (2)² - 4(2) + 5
= 4 - 8 + 5
= -4 + 5
= 1
RHS = 0
LHS ≠ RHS
Therefore, x² - 4x + 5 = 0 does not have 2 as a root.
B) x² + 3x - 12 = 0
Put x = 2
LHS: x² + 3x - 12
= (2)² + 3(2) - 12
= 4 + 6 - 12
= 10 - 12
= -2
RHS = 0
LHS ≠ RHS
Therefore, x² + 3x - 12 = 0 does not have 2 as a root.
C) 2x² - 7x + 6 = 0
Put x = 2
= 2(2)² - 7(2) + 6
= 8 - 14 + 6
= 14 - 14
= 0
RHS = 0
LHS = RHS
Therefore, 2x² - 7x + 6 = 0 has 2 as a root.
D) 3x² - 6x - 2 = 0
LHS: 3x² - 6x - 2
= 3(2)² - 6(2) - 2
= 12 - 12 - 2
= -2
RHS = 0
LHS ≠ RHS
Therefore, 3x² - 6x - 2 = 0 does not have 2 as a root.
✦ Try This: Which of the following equations has 2 as a root?
- x² - 4x + 5 = 0
- x² + 3x - 12 = 0
- 2x² - x - 6 = 0
- 3x² - 6x - 2 = 0
☛ Also Check: NCERT Solutions for Class 10 Maths Chapter 4
NCERT Exemplar Class 10 Maths Exercise 4.1 Problem 3
Which of the following equations has 2 as a root, a. x² - 4x + 5 = 0, b. x² + 3x - 12 = 0, c. 2x² - 7x + 6 = 0, d. 3x² - 6x - 2 = 0
Summary:
The equation 2x² - 7x + 6 = 0 has 2 as a root
☛ Related Questions:
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