Answer:

Step-by-step explanation:
Since interest is compounded semi-annually (half a year or 6 months), in a spawn of 2 years, the interest will have been compounded 4 times. As given in the problem, each time the interest is compounded, the new balance will be 107% or 1.07 times the amount of the old balance.
Therefore, we can set up the following equation to find the new balance after 2 years:

Answer:
3x - (15 x 3) = 90
or
3x - 45 = 90
Explanation:
there are 3 boxes. We don't know how many are in them yet, so we write this as 3x. However, we know that we give away 15 to 3 different teachers. 15 x 3 = 45
Therefore the first part is 3x - 45
We also know that in the end we have 90 left.
So our final equation is:
3x - 45 = 90
Answer:
1,319.83721
Step-by-step explanation:
Answer:
4000
Step-by-step explanation:
36kg = 36000g
36000g/9 bags = 4000g