To solve the equation 6.24(x+5.9)=20.22 , the first step is to reverse the multiplication. What number should both sides be divided by?

To reverse the multiplication in an equation, we need to divide both sides of the equation by the value multiplied to the variable.

In this case, the variable x is multiplied by 6.24. Therefore, to reverse the multiplication, both sides should be divided by 6.24.