Hey!
Let's switch the equation around:
[tex] 52 - 7 = 9x [/tex]
The sign changes when moved to the other sign. At first, it was (+), now it's (-).
First do 52 - 7
[tex] 52 - 7 = 45 [/tex]
That leaves you with:
[tex] 45 = 9x [/tex]
Divide both sides by 9
[tex] \frac{45}{9} = \frac{9x}{9} [/tex]
[tex] \framebox{x = 5} [/tex]
