[latex]- \frac{3}{4} \alpha =-9[/latex]

[latex]- \frac{3}{4} \alpha =-9 [/latex] [latex] \alpha =-9:(- \frac{3}{4} )[/latex] [latex] \alpha = \frac{9*4}{3}[/latex] [latex] \alpha =3*4=12[/latex]