[tex] \frac{17}{18} [/tex]-[tex] \frac{8}{9} [/tex]=x
You must find a common denominator(bottom)
[tex] \frac{8}{9} [/tex]×[tex] \frac{2}{2} [/tex]=[tex] \frac{16}{18} [/tex]
[tex] \frac{17}{18} [/tex]-[tex] \frac{16}{18} [/tex]=[tex] \frac{1}{18} [/tex]
Your answer is x=[tex] \frac{1}{18} [/tex]