Hello there. To solve this question, we'll have to remember some properties about set up an equation and solving them.
"Let y be an unknown number. 18 times a number minus 97 is equal to 9 less than the number."
We need to find this number.
Starting with the equation:
[tex]18y-97=y-9[/tex]On the left hand side, we have 18y as 18 times the number, then subtracted 97 for the minus 97 part. On the right hand side, 9 less than the number is represented as the number minus 9.
So, subtract y - 97 on both sides of the equation
[tex]\begin{gathered} 18y-97-(y-97)=y-9-(y-97) \\ 18y-97-y+97=y-9-y+97 \\ 17y=88 \end{gathered}[/tex]Divide both sides of the equation by a factor of 17
[tex]\begin{gathered} \frac{17y}{17}=\frac{88}{17} \\ \\ y=\frac{88}{17} \end{gathered}[/tex]This is the number we've been looking for.