Minta tolong yaa, ini soal thatquiz hehe

m1v1 + m2v2 = m1v1' + m2v2'
4 × 5 + 6 × (-4) = 4 × (-4) + 6v2'
20 - 24 = -16 + 6v2'
-4 = -16 + 6v2'
12 = 6v2'
v2' = 2 m/s