you have to times 9 by 5 which gives you 45. then you will know that b is 45 as if you subistue it into your equation it will become 45 divided by 5 gives you 9 and you know that is correct.
so if for examples you have to find A .. A/3 =9 you have to times 3 by 9 which gives you 27 you do this as you are doing the opposite to try and find your value. after you do 3 x9. you will know that 27 is you answer. so if you subsitue it into the equation it would become 27/ 3 = 9 and you know that is correct.