It can help because 9×4 =36, and 9×8=72. if you divide 72 by 2 you get 36 which is the answer to 9 ×4. basically because nine is the same in both problems you are multiplying by 4 (and you know 4 is half of 8) you can assume that multiplying the sum of 4 and 9 that you will get the sum of 8 and 9.
EHRP, EHFG, EFPQ Does that make sense?
Answer:
3 customers
Step-by-step explanation:
Rate of arrival (λ) = 15 per hour
Service rate (μ) = 20 per hour
The number of customers in a system given the arrival rate and the mean service rate is given by:

Applying the given data:

The average number of customers in the system is 3 customers.
I think there is no simplified fractions for this number it will be the same -4/17
It will be 3a+ 4b^2 =50 that’s what I get at least