Question

Find the value of k for which x²+5kx+16=0 has real and equal roots

Answer 1

Solution :

Compare x² + 5kx + 16 = 0 with

ax² + bx + c = 0 we get,

a = 1 , b = 5k , c = 16

discreminant ( ∆ ) = 0

[ given equal roots ]

b² - 4ac = 0

=> ( 5k )² - 4 × 1 × 16 = 0

=> ( 5k )² - 64 = 0

=> ( 5k )² - 8² = 0

=> ( 5k + 8 )( 5k - 8 ) = 0

=> 5k + 8 = 0 or 5k - 8 = 0

5k = -8 or 5k = 8

k = -8/5 or k = 8/5

Therefore ,

k = -8/5 or k = 8/5

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Answer 2

HEY MATE HERE IS YOUR ANSWER IN ATTACHMENT