For this case, the first thing we must do is define a variable.
We have then:
x: unknown number
Doing the multiplication we have:

From here, we clear the value of x.
We have then:

Therefore, we have:
Answer:
7 times 1/7 equals 1
2 x (n - 6)
(2 x n - 2 x 6)
(2n - 2 x 6)
2n - 12
I think it’s b but don’t take my word for it