3x + 5 [tex] \geq [/tex] 7
Subtract 5 to both sides so
3x + 5 - 5 [tex] \geq [/tex] 7 - 5
3x [tex] \geq [/tex] 2
Divide 3 to both sides
3x [tex] \geq [/tex] 2
[tex] \frac{3x}{3} \geq \frac{2}{3} [/tex]
Cancel out the 3 on the left side,
[tex] \frac{2}{3} = \frac{3}{2}[/tex]
[tex]x \geq 4[/tex]