Respuesta :

Answer:

(B.) -7k+21

Step-by-step explanation:

Your first step should be to solve your original expression.

-7×6=-42

-7x-3=21.

You're finishing numbers are -42 and 21.

-7k can equal to -42 if k is 6.

So we can use -7k

Since -7x-3=21, Then the answer would have to be:

-7k+21.