12 over 4 3rds is equal to 12 times three over four, which we could use 12 over one times three over four. 12 divided by four is three, so this is going to be equal to nine. 3 4ths of 12 is nine. So this, we could rewrite this, we could write this as nine x to the 4 3rd power. So if we evaluate it at eight, this is going to be nine times eight to the 4 3rds power, and from that, we're going to subtract, it evaluated at negative one. So this is going to be nine times negative one to the 4 3rd power. So what is eight to the 4 3rd power?