To evaluate the expression \( 10(3w - 2y) \) when \( w = 2 \) and \( y = 5 \), we first substitute the values of \( w \) and \( y \) into the expression:
\[ 10(3(2) - 2(5)) \]
Now, calculate \( 3(2) \) and \( 2(5) \):
\[ 3(2) = 6 \] \[ 2(5) = 10 \]
Now substitute these results back into the expression:
\[ 10(6 - 10) \]
Now calculate \( 6 - 10 \):
\[ 6 - 10 = -4 \]
Now multiply by 10:
\[ 10(-4) = -40 \]
So the final result is \(-40\).
Therefore, the answer is:
\(-40\)