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# If X = 1 is a Common Roots of the Equations Ax2 + Ax + 3 = 0 and X2 + X + B = 0, Then Ab = - Mathematics

MCQ

If x = 1 is a common roots of the equations ax2 + ax + 3 = 0 and x2 + x + b = 0,  then ab =

#### Options

• 3

• 3.5

• 6

• -3

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#### Solution

x = 1is the common roots given quadric equation are ax^2 + ax + 3 = 0, and x^2 + x + b= 0

Then find the value of q.

Here, ax^2 + ax + 3 = 0 ….. (1)

x^2 + x + b = 0….. (2)

Putting the value of x = 1 in equation (1) we get

a xx 1^2 + a xx 1 +3 = 0

a+a + 3 = 0

2a = -3

a = -3/2

Now, putting the value of x = 1 in equation (2) we get

1^2 + 1+b = 0

2 +b = 0

b = -2

Then,

ab = (-3)/2 xx (-2)

=3

Is there an error in this question or solution?
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#### APPEARS IN

RD Sharma Class 10 Maths
Chapter 4 Quadratic Equations
Q 12 | Page 83
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