sint+ cost = 32-8m5m (adding both equations and rearranging)
(50(cost+sint) + 5m)(cost-sint)=0 (subtracting both equations)
=> sint + cost = -m/10 OR tant = 1
Equating the bolded parts
=> -m10 = 32-8m5m
=> -5m2 = 320 - 80m
=> m2 - 16m + 64 = 0
=> (m-8)2 = 0
=> m=8