Remark
You'll see it a whole lot easier if you make a substitution so that it looks like something you have already seen
Solution
let y = x^2
x^4 = x^2 * x^2
x^4 = y * y
x^4 = y^2
Now the expression becomes
y^2 + 8 y - 9 = z
(y + 9)(y - 1) = z
Now put the x^2 back in.
(x^2 + 9) ( x^2 - 1) = z
x^2 - 1 becomes x + 1 and x - 1. At this level x^2 + 9 can't be factored.
Answer
(x^2 + 9) (x + 1)(x - 1)
280 = 20x + 100
20 * 9 = 180
x = 9
Check you answer :
280 = 20 ( 9 ) + 100
280 = 180 + 100
280 = 280 . True statement
The correct answer is E. A fundamental basis of regression analysis is the assumption of the existence of two independent variables for every dependent variable.
Regression analysis is a statistical method that examines the dependence of a response variable on selected explanatory variables.
When studying the dependence between quantities and trying to describe a given functional dependence on a given formula, it is assumed that the dependence consists of a precisely determinable component and a random component. The relationship with this assumption is called the regression model.
Learn more about regression analysis in brainly.com/question/1305938
Answer:
equation ---> 120+10(m)=150+4(m)
m= number of months
(By the way the answer would be 5 months)
Step-by-step explanation:
