In this video going to look at the division law for indices previously we looked at the multiplication law of indices, where we realize that when you multiply these together, you would add the powers when you divide, then you subtract the powers so a to the power 6 divided by a to the power 3 equals a to the power 3, because 6 subtract 3 is free, a really common wrong answer for this question is a to the power 2, because people actually divide the powers rather than to subtract them and do 6 divided by free to get two? But it’s not it’s a subtraction? So a similar thing on this next question. Apart from we have coefficients, we have a 20 and a 5, so we actually divide these 20 divided by 5 gives you 4, and then we use the division law with the indices, so b to the 7 divided by b, squared 7, take away? 2 is 5, so it’s 4 b to the power 5.
This last question is just another way of writing a divide sign? So we have a fraction here, but that’s just like a divide. So we carry on like we would with this previous question! It’s just written slightly differently, so 12 divided by 3 is 4, and then we use the indices. Division law so x to the 7 divided by x to the 3, is x to the 4, because 7 take 3 is 4 and then on the y’s? We have y squared divided by y to the 5 so to subtract. 5 is negative. 3 here are some questions for you to try yourself press pause and have a go at those, and then press play and i will take you through the answers. Ok, here are the answers, then, for the first question, 6 divided by 3 is 2 and then x to the 7 divided by x, squared is x to the 5 for this next one 15 divided by 5 is free and then y to the 9 divided by y! Cubed is y to the 6, and then we have 11 a squared and then 2 b to the 8th. It’s remembering that be here justbe to the power one, this one’s slightly different, because we have a negative sign at the front. That just means we have that with a negative in our answer, but it comes out as 4 c to the power 3 and this one here we have 2 because 10 divided by 5 is 2 x cubed, and this one here, 5 x to the 4 again remembering there’s a power 1 here that we haven’t written y to the power 6 this one here, 6 a to the negative 6 and finally 5 b, and this one. You have to be a bit careful because it’s negative to subtract 7, which is negative 9, and that’s your video on the vision law for indices.
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