Answer:
You have to take 15 pens to get at least one red pencil.
Step-by-step explanation:
If there were one red and 6 green pens, there would be more red than green pens.
If there were 3 or more blue and thus 18 or more green pens, the number of pens would be over 20.
So there must be 2 blue, 12 green and thus 6 red pencils. So you have to take at least 15 pens to be sure that you got a red one.
Answer:


Step-by-step explanation:
Given

Solving (a): Write as inverse function

Represent a(d) as y

Swap positions of d and y

Make y the subject


Replace y with a'(d)

Prove that a(d) and a'(d) are inverse functions
and 
To do this, we prove that:

Solving for 

Substitute
for d in 




Solving for: 

Substitute 5d - 3 for d in 

Add fractions



Hence:

Answer:
61-4g
Step-by-step explanation:
ygbhc
Answer:
{−1008,−504,−252,−126,…}
Step-by-step explanation:
-504÷(-1 008)=0.5
(-252)÷(-504)=0.5
(-126)÷(-252)=0.5
In this sequence ,we multiply by 0.5 each time to get the next term
then it’s a geometric sequence.