Start with the sum of x and 9, giving the expression
[tex]x + 9[/tex]
This is divided by 2 so
[tex] \frac{x + 9}{2} [/tex]
This equals 3x so the equation is
[tex] \frac{x + 9}{2} = 3x[/tex]
This can the be solved.
Multiply both sides by 2 to get
[tex]x + 9 = 6x[/tex]
Then take x from both sides
[tex]9 = 5x[/tex]
Divide by 5 to get the value for x
[tex]1.8 = x[/tex]
