Your answer is 9s^2-9st+6st-6t^2
You can rewrite that as:
a^2-4ab+6ab-24b^2 then factor 1st and 2nd pair of terms.
a(a-4b)+6b(a-4b) so you have
(a+6b)(a-4b)
Mean is the average....so you add all the numbers and then divide by how many numbers there were.
12 + 13 + 15 + 28 + 28 +30 + 42 = 168
since there are 7 numbers, you divide 168 by 7.
168/7 = 24
Therefore, 24 is the mean.
The flag is Japan I believe.
Hope this helps!
Answer:
4.92
Step-by-step explanation:
615 divided by 125 equals to 4.92