1) a) [tex]\left\{\begin{matrix} x=x_0+v_0t\\ x=18-6t \end{matrix}\right. \Rightarrow \begin{matrix} x_0=18(km)\\ v_0=-6(km/h)\\ t_0=0(h) \end{matrix}[/tex]
b) [tex]t=4(h)\Rightarrow x=18-6.4=-6(km)[/tex]
c) [tex]s=v.t=6.2=12(km)[/tex]
2)
a) [tex]\left\{\begin{matrix} x=x_0+v_0t\\ x=-10+4t \end{matrix}\right. \left\{\begin{matrix} x_0=-10(km)\\ v_0=4(km/h)\\ t_0=0(h) \end{matrix}\right.[/tex]
b) [tex]t=4(h)\Rightarrow x=4.4-10=6(km)[/tex]
c) [tex]s=v.t=4.2=8(km)[/tex]
3)