Answer:
n = m - 7 or n = -m - 7
Explanation:
Solve for n:
m^2 - (n + 7)^2 = 0
The left hand side factors into a product with two terms:
(-7 + m - n) (7 + m + n) = 0
Split into two equations:
-7 + m - n = 0 or 7 + m + n = 0
Subtract m - 7 from both sides:
-n = 7 - m or 7 + m + n = 0
Multiply both sides by -1:
n = m - 7 or 7 + m + n = 0
Subtract m + 7 from both sides:
Answer: n = m - 7 or n = -m - 7