Kinematics help

Im really confused about this kinematics question?

If it starts from rest, then the velocity at time $t$ is given by $v=at$ and the displacement is given by $s=\frac{1}{2}at^2$.

At some time $T$ the particle has displacement from the origin as $s_1=\frac{1}{2}aT^2$, and 4 seconds later it has a displacement $s_2 = \frac{1}{2}a(T+4)^2$.

We know that the difference between the two displacements is 12m therefore $s_2 - s_1 = 12 = \frac{1}{2}a[(T+4)^2-T^2]$.

Doing the same with the next piece of information yields $30 = \frac{1}{2}a[(T+9)^2-(T+4)^2]$

You can use the two to determine $T$, and hence $a$. Hence answer the rest of the questions.

Would my method still work?

It's hard to see what you're trying to do.

So have a go and see if you get the right answers.

If it starts from rest, then the velocity at time $t$ is given by $v=at$ and the displacement is given by $s=\frac{1}{2}at^2$.

At some time $t=T$ the particle has displacement from the origin as $s_1=\frac{1}{2}aT^2$, and 4 seconds later it has a displacement $s_2 = \frac{1}{2}a(T+4)^2$.

We know that the difference between the two displacements is 12m therefore $s_2 - s_1 = 12 = \frac{1}{2}a[(T+4)^2-T^2]$.

Doing the same with the next piece of information yields $30 = \frac{1}{2}a[(T+9)^2-(T+4)^2]$

You can use the two to determine $T$, and hence $a$. Hence answer the rest of the questions.

Im really confused about this kinematics question?