Hey there!
n - 18 = -6
ADD 18 to BOTH SIDES
n - 18 + 18 = -6 + 18
CANCEL out: -18 + 18 because that gives you 0
KEEP: -6 + 18 because that helps solve for n
n = -6 + 18
n = 12
Answer: n = 12
Good luck on your assignment and enjoy your day!
~Amphitrite1040:)