7•y=100-9

To solve the equation \( 7y = 100 - 9 \), first simplify the right side:

\[ 100 - 9 = 91 \]

Now the equation becomes:

\[ 7y = 91 \]

Next, divide both sides by 7 to solve for \( y \):

\[ y = \frac{91}{7} \]

Calculating the division:

\[ y = 13 \]

So the solution is:

\[ y = 13 \]