 Hello and welcome to the session. In this session we discussed the following question which says by what number should minus 15 to the power minus 1 be divided so that the quotient is minus 3 to the power minus 1. Now if we are given a rational number say a upon b then a upon b to the power minus 1 is equal to b upon a. This is the key idea to be used in this question. Let's move on to the solution now. We need to find the number by which minus 15 to the power minus 1 would be divided so that we get the quotient as minus 3 to the power minus 1. So we take let the required number be equal to x so minus 15 to the power minus 1 would be divided by x so that we get the quotient as minus 3 to the power minus 1. This means minus 15 to the power minus 1 upon x is equal to minus 3 to the power minus 1. Or you can say we get x is equal to minus 15 to the power minus 1 upon minus 3 to the power minus 1. Or you can say we get x equal to minus 15 upon minus 3 this whole to the power minus 1. Now this minus minus gets cancelled. Now using the key idea it says that for any rational number a upon b a upon b to the power minus 1 is equal to b upon a. So we say this gives us x is equal to 3 upon 15. Now 3 5 times is 15 so we now have x is equal to 1 upon 5. Or we can also say that x is equal to 5 to the power minus 1. Hence we say that minus 15 to the power minus 1 should be divided by 5 to the power minus 1 so that the quotient is minus 3 to the power minus 1. So 5 to the power minus 1 is our final answer. This completes this session. Hope you have understood the solution for this question.