Question

if the equation x2+2(k+2)+9k=0 has equal roots find the value of k​

Answer 1

Step-by-step explanation:

if eq. has equal root then,

D=0

b²-4ac=0

{2(k+2)}²-4×1×9k=0

4(k²+4k+4)-36k=0

4k²+16k+16-36k=0

4k²-20k+16=0

4(k²-5k+4)=0

k²-5k+4=0

k²-4k-k+4=0

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

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

either k-1=0 or k-4=0

k-1=0 k-4=0

k=1 k=4

hence k=1 or 4

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