Question

(a + b, c + 1) is a solution of the equation y = 2x, If a = 2k, b = 5k, c = 7k; k ≠ 0 and k ∈ R, then find the value of k.

Answer 1

y=2x
c+1=2(a+b)
7k+1=2(2k+5k)
7k+1=14k
7k=1
k=1/7

Answer 2

Solution :

It is given that ,

a = 2k , b = 5k , c = 7k , k ≠ 0 , k€ R

( a + b , c + 1 )

= ( 2k + 5k , 7k + 1 )

= ( 7k , 7k + 1 )

Now ,

( a + b , c + 1 ) = ( 7k , 7k + 1 ) is a

solution of y = 2x

=> 7k+ 1 = 2( 7k )

=> 7k + 1 = 14k

=> 1 = 14k - 7k

=> 1 = 7k

=> 7k = 1

=> k = 1/7

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