Answer: x=3
work: x+9=12
x=12-9
x=3
Answer:
Median
Step-by-step explanation:
You need to arrange the numbers in order by size.
Then if there is an odd number of terms the median in the middle term. If there is is an even amount of terms then what you do is add 2 then divide by 2
If you would like to find the product (n + 8) * (n - 2), you can do this using the following steps:
(n + 8) * (n - 2) = n * n - 2 * n + 8 * n - 8 * 2 = n^2 + 6 * n - 16
The correct result would be n^2 + 6 * n - 16.
Using basic math we will eventually come with an answer of 9.
Math you do in your head
example you can do 10 tiemes 3=30 in your head
that is mental math
you might have a hard time doig 19 times 23 so you would use a calulator then it would not be mental math
it's helpful if at the supermarket or at a resaurant
mental math is math done in the mind
