If one root of the equation 2 x 2 + a x + 6 = 0 is 3, then the value of a is ___________. Options: A . &nbsp -8 B . &nbsp 7 C . &nbsp 3 D . &nbsp 5

If one root of the equation 2x2+ax+6=0 is 3, then the value of a is _________

Question

If one root of the equation $2 x^{2} + a x + 6 = 0$ is 3, then the value of a is ___________.

Options:

A . -8

B . 7

C . 3

D . 5

Answer: Option A
:
A

If one root of the equation $2 x^{2} + a x + 6 = 0$ is 3, then substituting $x = 3$ will satisfy the equation.

$2 (3)^{2} + 3 a + 6 = 0$

$\Rightarrow 18 + 3 a + 6 = 0$

$\Rightarrow 24 + 3 a = 0$

$\Rightarrow a = - 8$

Was this answer helpful ?

Next Question

Question 1. The roots of 2x2–6x+8=0 are ___________. ....

Question 2. Using the method of completion of squares find one of the roots of the equation 2x2−7x+3=0. Also, find the equa....Also, find the equation obtained after completion of the square.

Question 3. If the equation x2+2(k+2)x+9k=0 has equal roots, then values of k are __________. ....

Question 4. If the equation x2+2(k+2)x+9=0 has equal roots, then find the values of k. ....

Question 5. A can do a piece of work in x days and B can do the same work in x+16 days. If both working together can do it in 15 d....do it in 15 days, find the value of x.

Question 6. Solve for x if 4(2x+3)2−(2x+3)−14=0. ....

Question 7. If one root of the quadratic equation 2x2+ax−6=0 is 2, find the value of a. ....

Question 8. The product of 2 consecutive natural numbers is 72. Find the numbers. ....

Question 9. If the speed of a train is reduced by 40 km/hr, it takes 20 minutes more to cover 1200 km. Find the speed of the....to cover 1200 km. Find the speed of the train.

Question 10. Find the value of k for which x2–4x+k=0 has coincident roots. ....

Chapter 1 - GLOBAL STEEL SCENARIO & INDIAN STEEL INDUSTRY Part 1 : (13-04-2024) INDUSTRY AND COMPANY AWARENESS (ICA)

Direction Sense Test Part 1 Reasoning (Hindi)

Chapter 1 - RMHP / OHP / OB & BP Part 1 : (14-02-2024) GPOE

Cube & Cuboid Part 1 Reasoning (Hindi)

Data Interpretation (DI) Basic Concept Reasoning (Hindi)

Counting Figures Part 1 Counting Of Straight Lines Reasoning (Hindi)

Sail E0 free webinar Webinars

Real Numbers Part 7 Class 10 Maths

Real Numbers Part 1 Class 10 Maths

Polynomials Part 1 Class 10 Maths

DSP Combined 1 Free Revision Test SAIL JO E-0

GPOE / GPA Combined 1 Free Revision Test SAIL JO E-0

BSP Plant Specific Review Test SAIL JO E-0

BSL Combined 1 Free Revision Test SAIL JO E-0

GFM Combined 1 Free Revision Test SAIL JO E-0