Adams Bashforth method question

Adams Bashforth method question

Consider an ordinary differential equation
$$\dfrac{dy}{dt} = 0.5y - 2.5\sin(t),~~ 0 <t \le 12$$
for the function $y(t)$ with the initial condition $y(0) = 2$
Derive equations for Adams-Bashforth three-step method applied to this
problem. Provide an expression for the value of the approximate solution
wi+1 at a timestep ti+1 in terms of previously calculated values. Take
required starting values from the exact solution $y(t)= 2 \cos(t) +
\sin(t)$. Provide the starting values.
Write a Matlab code implementing the method for this problem. Provide the
text of the code