The process is:
C = 2nr
2nr = c
r (2n) = c

That's the answer☝️☝️☝️☝️
or maybe this one
r = 2n + c
sorry, I'm unsure, it has been too long since I studied that...
Answer:
The small balloon bouquet uses 7 balloons and the large one uses
18 balloons.
Step-by-step explanation:
Let's say that small balloon bouquets are S and large balloon bouquets are L. For the graduation party the employee assembled 6 small bouquets and 6 large bouquets, the total number of balloon used is 150. To put the sentence into an equation will be:
6S + 6L= 150
S+L= 25 ----> 1st equation
For Father's Day, the employee uses 6 small bouquet and 1 large bouquet, the total number of balloons used is 60. The equation will be:
6S + 1L= 60
1L= 60- 6S ----> 2nd equation
We can solve the number of small balloon bouquet by substitute the 2nd equation into 1st. The calculation will be:
S+L = 25
S+ (60-6S)= 25
-5S= 25-60
-5S= -35
S= -35/-5
S=7
Then we can find L by substitute S value to 1st or 2nd equation.
S+L=25
7+L=25
L=18
Hope this helps ;)
The answer is A. I hope I helped
When applying indirect proofs, we assume the negation of the conclusion is true, and show that this assumption would lead to nonsense, or contradiction.
In our case we assume a is not smaller than 7, that is we assume a≥7.
a≥7 then, multiplying both sides by 3:
3a≥21, then, adding both sides 7:
3a+7≥28,
which is a contradiction because 3a+7 is smaller than 28.
So our assumption is wrong, which means the opposite of it is correct.
Answer: assume a≥7