Question

how to factor 7t(n-4)-(4-n)

Answer 1

I would rewrite the 2nd portion

7t (n-4) + (n-4) = 0

now combine like terms

(7t + 1) (n-4) = 0

Answer 2

how did you do that?

Answer 3

Like I said, I would rewrite the 2nd portion.
4-n multiply each term by -1 = n -4
so I then "pull that -1" out

7t(n-4)-(4-n) = 0
7T (N-4) -(-1) (N-4) = 0
7T (N-4) +1 (N-4) = 0 what is common? so factor it out
(7T +1) (N-4) = 0

think of it as distribution in reverse

Answer 4

-(4-n) => -1*4 -1*-n => -4 +n => (n-4)

Answer 5

recall same signs multiplied give +
different signs multiplied give -