Let's start with just regular fractions and let's ignore the negative sign for now. 3/10 x 4/5. Since 10 and 4 are multiples of 2, we can simplify it. so it will be 3/2 x 2/5 and you'll get 6/10. 2 can still get into 6 and 10, so the simplest form would be 3/5. Simply add the negative sign and your answer is -3/5