To distribute \( \frac{5}{1} \) (which is the same as 5) to the expression \( (5s - 15) \), you can apply the distributive property as follows:
\[ 5 \cdot (5s - 15) = 5 \cdot 5s - 5 \cdot 15 \]
This gives:
\[ 25s - 75 \]
Now, substituting this back into the equation, we have:
\[ 25s - 75 = 9s + 9 \]
Next, to isolate \( s \), we will move all the terms involving \( s \) to one side and the constant terms to the other side. Let's subtract \( 9s \) from both sides:
\[ 25s - 9s - 75 = 9 \]
This simplifies to:
\[ 16s - 75 = 9 \]
Now, add \( 75 \) to both sides to isolate the term with \( s \):
\[ 16s = 9 + 75 \]
This further simplifies to:
\[ 16s = 84 \]
Finally, divide both sides by \( 16 \) to solve for \( s \):
\[ s = \frac{84}{16} \]
To simplify \( \frac{84}{16} \):
The greatest common divisor of 84 and 16 is 4, so we can simplify:
\[ s = \frac{84 \div 4}{16 \div 4} = \frac{21}{4} \]
Thus, the solution for \( s \) is:
\[ s = \frac{21}{4} \] or \( 5.25 \) in decimal form.