can someone explain the answers to the question:

Question

Consider the following set of equations, where s, s0 and r have units of length, t has units of time, v has units of velocity, g and a have units of acceleration. Take k to be dimensionless.Identify if these are dimensionally correct or incorrect.
1)v^2= 2as + kav
2)s = s0 + kat^2
3)a =v^2/r+kv/t
4)t =v/a
5)t = k square root of s/g

Answer 1

1)v^2= 2as + kav
m²/s²=(m/s²)•m +(m/s²)•(m/s)
=> incorrect
2)s = s0 + kat^2
m= m + (m/s²)•s²=> correct
….
3 incorrect
4 correct
5 correct