How to do 18b ? pls explain too thanks

Answer:
m² + 9n² + 4m - 12n - 6mn + 4
Step-by-step explanation:
18b
(2+m-3n)² = (2+m-3n)(2+m-3n)
= 2*2 + 2*m + 2*-3n + m*2 + m*m + m*-3n - 3n*2 -3n*m - 3n*-3n
= 4 + 2m - 6n + 2m + m² - 3mn - 6n - 3mn + 9n²
= m² + 9n² + 2m + 2m - 6n - 6n - 3mn - 3mn + 4
= m² + 9n² + 4m - 12n - 6mn + 4
Answer:
(2+m-3n)(2+m-3n)
Step-by-step explanation:
Here's solution:
(2+m-3n)(2+m-3n)
4 + 2m - 6n + 2m + m^2 - 3mn - 6n - 3mn + 9n^2
4 + 4m - 12n + m^2 - 9mn + 9n^2
I hope this is right, I'm a bit tired.
Hope this helps, and have a good day :)!