jonnburton
Junior Member
- Joined
- Dec 16, 2012
- Messages
- 155
Hi,
I've been working on indices and am having a little difficulty fully understanding it. The following is an example of a question which I got wrong and am unable to see why. I would be grateful for any indicators as to where my thinking is off track.
Simplify the following:
\(\displaystyle 16a^-2b^2c^-3 * 2 (abc)^-2\)
Multiplying out the brackets gives:
16a^-2 * b^2 * c^-3 * 2a^-2 *2b^-2 * 2c^-2
= 32a^-4 * 2b^0 * 2c^-5
However, the answer the book gives is:
32a^-4b^0c^-5
My question here is, what happens to the 2 before the brackets in the original equation; why does this dissapear? (I would have thought that b^2 * 2b^-2 = 2b^0, and c^-3 * 2c^-2 = 2c^-5 ...)
I've been working on indices and am having a little difficulty fully understanding it. The following is an example of a question which I got wrong and am unable to see why. I would be grateful for any indicators as to where my thinking is off track.
Simplify the following:
\(\displaystyle 16a^-2b^2c^-3 * 2 (abc)^-2\)
Multiplying out the brackets gives:
16a^-2 * b^2 * c^-3 * 2a^-2 *2b^-2 * 2c^-2
= 32a^-4 * 2b^0 * 2c^-5
However, the answer the book gives is:
32a^-4b^0c^-5
My question here is, what happens to the 2 before the brackets in the original equation; why does this dissapear? (I would have thought that b^2 * 2b^-2 = 2b^0, and c^-3 * 2c^-2 = 2c^-5 ...)