To simplify the expression \( 9(7r - 3s + 10) \), you can distribute the 9 to each term inside the parentheses:
\[ 9(7r) - 9(3s) + 9(10) \]
Calculating each term:
\[ 9 \cdot 7r = 63r \] \[ 9 \cdot -3s = -27s \] \[ 9 \cdot 10 = 90 \]
Now, combine these results:
\[ 63r - 27s + 90 \]
So, the simplified expression is:
\[ \boxed{63r - 27s + 90} \]