posted by danny on .
use mental math and the distributive property to simplify 25(-99)and 19x21
Round the numbers so that they are easy to do you your head.
exsample for danny 25(-99) what is the answer thanks
What she is trying to say it, change the numbers into easier number that you can multipy in your head.
Change -99 to -100
Then the question would be 25(-100)
which is equal to -2500
but you added on a -25
so now you you have to add on a positive 25;
That should be the right answer.
Try doing the other one on your own.