Math, asked by itszehra29, 10 months ago

Solve the following
kx²+(2k+4)x+9

Answers

Answered by Aloi99
4

Answer:

Here is ur answer↓

k=4and k=1

Step-by-step explanation:

Your Question- kx²+(2k+4)x+9 has equal roots find value of k?

Solution:-

Using Discriminant Formula

a=k b=(2k+4) c=9

d=-4ac

=>(2k+4)²-4×k×9=0

[°° Roots Are Real d=0]

4k²+16k+16-36k=0

4k²-20k=-16

4k²-20k+16=0---÷by4

=>-5k+4=0

Sum=-5

Product=1×4=4

-4×-1=4 Also,-4-1=-5

-k-4k+4=0

k(k-1)-4(k-1)=0

k-1=0

k=1

k-4=0

k=4

Hope you Understood

Answered by Rudra0936
10

  \boxed{\blue{ \boxed{ \huge{ \red{Question}}}}}

Find value of K for which the roots of the equation are equal

      \boxed{\blue{ \boxed{  \red{\huge{Answer}}}}}

Given equation

 \green{kx ^{2}  + (2k + 4)x + 9} = 0

Here a = k ,b = 2k+4 , c = 9

So to find the value of K we can apply the descriminent formula that is

 \bold{ \boxed{ \blue{b ^{2}  - 4ac}} }

So the

Now putting the value of a.b and c in the discriminent formula

 =  > (2k + 4) ^{2}  - \: 4 \times 9 \times k = 0 \\  \\  =  > 4k ^{2} \:  + 16 + 16k - 36k = 0 \\  \\  =  > 4k ^{2} - 20k + 16 = 0 \\  \\  =  >k ^{2}  - 5k + 4 = 0

Now let us apply Sridhar acchariyas formula to find the possible value of k

 =  > k =  \frac{ - b \:plusminus\:  \sqrt{b ^{2} - 4ac } }{2a}

 =  > k =  \frac{5 \: plusminus\sqrt{25 - 16} }{2} \\ =  >  \boxed{ \red{ k =  \frac{  5 \: pluaminus\: 3}{2} }}

Are the roots

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