Okay :)
Well first you need to do the multiplication.
5*2/5n=40*5
So 5*2=10 and 40 * 5=200
So now plug those numbers into the equation.
10/5n=200
Now we divide :) So 10/5=2
So what do we have left over??
2n=200
To find n we are just going to divide both sides by 2 so
200/2=100
So n=100
Hope this helps! If you need anymore help or further explanation jsut let me know!!! :)
