(solution) A car starts at a stationary position and accelerates at 1.5m/s^2

(solution) A car starts at a stationary position and accelerates at 1.5m/s^2

A car starts at a stationary position and accelerates at 1.5m/s^2 for 20 seconds and then decelerates at 0.5m/s^2 until coming to a standstill. How fat did the car travel? I saw multiple ways of doing this problem, and I am still so confused on how to get the answer. I started off by doing the integral of 1.5t since that is the velocity, and I am trying to get the position. But for the decelerates part, I don’t know if it is minus integral of 0.5t since that is the velocity?