To solve the equation \( 3 - 15x + 24 + 16x = 4x - 24 - 4x \), let's first combine like terms on both sides of the equation.
On the left side: \[ 3 + 24 - 15x + 16x = 27 + x \]
On the right side: \[ 4x - 4x - 24 = -24 \]
Now the simplified equation is: \[ 27 + x = -24 \]
The next best step to finish solving for \( x \) is to isolate \( x \) by subtracting 27 from both sides: \[ x = -24 - 27 \] \[ x = -51 \]
So, the next best step after simplifying is to subtract 27 from both sides.