Answer:
The length of EF = x = 18 cm
Option A is correct.
Step-by-step explanation:
Ware given perimeter of triangle = 97 cm
We need to find length of EF = x = ?
The length of EG = x+7
The length of EF = x
The length of GF = 3x
The formula used is: 
Putting values and finding x i.e length of EF

So, value of x=18 cm
The length of EF = x = 18 cm
Option A is correct.
The question requires stating the Null and Alternative hypothesis for the scenario described :
Answer:
H0 : μ = 24
H1 : μ < 24
Step-by-step explanation:
The claim or hypothesis to be tested in a statistical problem or analysis is the alternative hypothesis. This is usually the opposite of the Null hypothesis which is the usually the initial truth until there is significant evidence provided using statistical test to prove otherwise.
The null hypothesis, H0 in the scenario above is :
H0 : μ = 24 ( average battery life is 24 hours)
The alternative hypothesis is the claim, that is. The mean battery life not up to 24 hours ;
H1 : μ < 24
The common factor is 2 so: 2(4x+3) is the answer
C=8πab
Divide both sides by 8πb
c/(8πb) = a