The inclination is the angle of the line with respect to x-axis:
in our case, angle alpha is equal to 120 degrees:
[tex]\alpha=120[/tex]The slope m in the line equation
[tex]y=mx+b[/tex]is related to alpha by the tangent function, that is
[tex]m=\text{tan }\alpha[/tex]In our case, we have
[tex]\begin{gathered} m=\text{tan 120} \\ \sin ce\text{ tan120=-}\sqrt[]{3,}\text{ it yields} \\ m=-\sqrt[]{3} \end{gathered}[/tex]So, our line equation has the form:
[tex]y=-\sqrt[]{3}x+b[/tex]where b is the y-intercept, which is equal to -6.
Finally, the line equation is
[tex]y=-\sqrt[]{3}x-6[/tex]