Approximate solutions with explicit Euler steps
Use explicit (forward) Euler updates x[n+1]=x[n]+h and y[n+1]=y[n]+h f(x[n],y[n]). Evaluate each slope at the old point. Give exact values; do not round intermediate values
\[y'=3x+(-1)y+(0),\quad x_0=0,\ y_0=-1,\ h=\frac{1}{5}\]
Calculate one Euler step. Distinguish the derivative from the vertical increment