To reverse the multiplication by \(6.24\) in the equation \(6.24 (x + 5.9) = 20.22\), you should divide both sides of the equation by \(6.24\).
So, the correct step is:
\[ x + 5.9 = \frac{20.22}{6.24} \]
After performing the division on the right side, you can solve for \(x\):
- Calculate \( \frac{20.22}{6.24} \).
- Then, isolate \(x\):
\[ x = \frac{20.22}{6.24} - 5.9 \]
Thus, both sides should be divided by \(6.24\).