Question

1. If x=k be a solution of the quadratic equation
x2 + 4x + 3 = 0, then k -1 and
(a) 2 (b) 3 (c) 3
(d) - 2​

Answer 1

ANSWER:

k = ( -3 )

STEP BY STEP EXPLANATION:

( x +3 ) ( x +1 ) = 0

x = ( -3 ) , ( -1 )

CHECK -3 :

(-3)^2 + 4 * -3 + 3 = 0

9 + (-12) + 3 = 0

Therefore LHS = RHS

Therefore , k = -3

Answer 2

Given,

It is given that x= k is a solution of the quadratic equation x² + 4x + 3 = 0.

To find,

The value of k-1.

Solution,

The value of k-1 is (d) -2.

We can simply solve the given quadratic equation by finding its roots by splitting the middle term method.

       x² + 4x + 3 = 0

       x² +x + 3x +3

       x(x + 1) +3( x +1 )

        (x+1)  (x+3)

       x = -3, -1

       x = k (given)

       k = -3, -1

       k-1 for k = -3

       = -3-1

       = -4

      which is not in the options provided.

      k-1 for k = -1

      = -1-1

     = -2

Hence, the value of k-1 is (d) -2 if x=k be a solution of the quadratic equation x²+4x+3=0.