A particle's position along the x-axis is described by: x(t)=A t + B t²
where t is in seconds, x is in meters, and the constants A and B are given below.

​Randomized Variables

A = -4.3 m/s
B = 4.9 m/s​²

What is the velocity, in meters per second, of the particle at t​₁ = 3.0 s?