I need some help I’m just a little stumped

Answer:
m = (2A - kn)/k
Step-by-step explanation:
A = k/2 (m + n)
A = (k/2)m + (k/2)n distributive property
2A = km + kn multiply both sides by 2
2A - kn = km subtract kn from both sides
(2A - kn)/k = m divide both sides by k