[tex] \Large\leadsto \sf \frac{1}{2} (x \: + \: 9) \: = \: 3[/tex]
[tex]\Large\leadsto\sf\frac{1}{2} x \: + \: \frac{9}{2} \: = \: 3[/tex]
[tex] \Large\leadsto\sf \frac{2x \: +\: 18}{4} \: = \: 3[/tex]
[tex]\large \leadsto\sf 2x \: + \: 18 \: = \: 3 \: \times \: 4[/tex]
[tex]\large\leadsto\sf2x + \: 18 \: = \: 12[/tex]
[tex]\large\leadsto\sf2x \: = 12 \: - \: 18[/tex]
[tex]\large\leadsto \sf 2x \: = \: - 6[/tex]
[tex]\Large\leadsto\sf \: x \: = \: \cancel\frac { - 6}{2}[/tex]
[tex]\large\leadsto\sf \pmb{ \: x \: = \: - 3}[/tex]
