The equation is 9h = 90.
Let's begin. We have the statement :
⇒ When 9 is multiplied by a number, the result is 90.
To write our equation, we should first choose a letter to represent the variable. I'll choose h. Notice what follows :
⇒ 9 multiplied by h is 90
If we write 9 multiplied by h as 9h, we end up with :
⇒ 9h is 90
Which can be rewritten this way :
⇒ 9h = 90
Therefore, our equation is 9h = 90.