 Hello and welcome to the session. In this session we discussed the following question which says by what number should minus 8 whole to the power minus 1 be multiplied so that the product becomes 9 to the power minus 1? Before proceeding with the solution, let us discuss the key idea to be used for this question. We have a upon b be any rational number and m and n be any integers then we have a upon b whole to the power minus n is equal to b upon a whole to the power n. This is the key idea to be used in this question. Now let us move on to the solution. We take let the required number be x then we have minus 8 to the power minus 1 multiplied by x gives us 9 to the power minus 1. Now using this law we get 1 upon minus 8 into x is equal to 1 upon 9. So this gives us x upon minus 8 is equal to 1 upon 9 that is we get x is equal to minus 8 upon 9. So this is the required number that is we say minus 8 to the power minus 1 should be multiplied by minus 8 upon 9 so that the product becomes 9 to the power minus 1. So this completes the session. Hope you have understood the solution for this question.