Answer:

So then the correct answer is B. $200.
Step-by-step explanation:
Notation
Let X be the average contribution size before John makes his contribution.
Let Y be the total contribution size before John makes his contribution.
Let Z be John's contribution.
We know that for this case $ 75 represent the original average amount before the contribution with 50% increase so we can set up the following equation in order to find the original average amount

And solvong for X we got:

Now we can find the total contribution before the donation with the following proportion:


And then with the formula of average taking in count the 6 values we can find the size of donation Z like this:



So then the correct answer is B. $200.
Answer:
a) x² +1
b) x² +25
Step-by-step explanation:
a) (x+i)(x− i)
= x² - ( i ) x + ( i ) x - ( i)²
= x² - i² ∵ i² = -1
= x² - (-1)
= x² +1
b) (x+5 i)(x− 5i)
= x² - ( 5 i ) x + ( 5 i ) x - ( 5 i)²
= x² - 25 i² ∵ i² = -1
= x² - 25(-1)
= x² +25
we can also solve
using identity
(a + b)(a - b) = a² - b²
= (x+5 i)(x− 5i)
= x² - (5 i)²
= x² - 25 i²
= x² +25
Alright so .25 oz is 1/4 of 1oz. Therefore you take 28 and divide it by 4 and get 7.
Then take 3500 and divide it by 7 which makes 500 thumb tacks.
I think idk though.
3/5
.60 is equal to 6/10
you can simplify that to 3/5
its 3f(x) i just answered it