You can download the app Photomath, it gives you the answer and the explanation, anyways question 1 is n=-1 and question 2 is x=10
If I understand the problem correctly, here's the answer:
2 (3x+6) + 2 (2x+4)=94
6x+12+4x+8=94
10x+20=94
10x=74
X=74/10
X=37/5
Answer: 37
Step-by-step explanation:
As per given description in the question, we have
Population standard deviation : 
Critical value for 98% confidence interval = 
Margin of error : E= 1 mile per gallon
Formula we use to find the sample size :

i.e. 

Therefore , the number of automobiles should be used in the test =37