Step-by-step explanation:

a+b=a+7a=−(

3

−8

)

= 8a=

3

8

or =a=

3

1

And a×b=a×7a=

3

2k+1

⇒7a

2

=

3

2k+1

=7(

2

1

)

2

=

3

2k+1

(∵a=

3

1

)

⇒

9

7

=

3

2k+1

⇒

3

7

=2k+1

⇒

3

7

−1=2k⇒k=

3

2