Answer:
x > -7/12. This is the answer to this question.
Answer: 
Step-by-step explanation:
Given : Sample size : n= 9
Degree of freedom = df =n-1 =8
Sample mean : 
sample standard deviation : 
Significance level ; 
Since population standard deviation is not given , so we use t- test.
Using t-distribution table , we have
Critical value = 
Confidence interval for the population mean :

90% confidence interval for the mean value will be :






Hence, the 90% confidence interval for the mean value= 
Hello there!
8m² - 4(7m³ + 5n²)
You wanna start by using the distributive property
=8n² - (-4)(7m³) + (-4)(5n²)
= 8n² - 28m³ - 20n²
= -28m³ - 12m²