Answer:
second option
Step-by-step explanation:
Given
+ 6x² + 5 = 0
let u = x², then
u² + 6u + 5 = 0 ← in standard form
(u + 1)(u + 5) = 0 ← in factored form
Equate each factor to zero and solve for u
u + 1 = 0 ⇒ u = - 1
u + 5 = 0 ⇒ u = - 5
Change u back into terms of x, that is
x² = - 1 ( take the square root of both sides )
x = ± = ± i ( noting that
= i ), and
x² = - 5 ( take the square root of both sides )
x = ± = ±
= ±
×
= ± i
Solutions are x = ± i and x = ± i
The equation to show the depreciation at the end of x years is
Data;
This is an equation written to represent a word problem into mathematical statement and this is easier to solve.
To write a linear depreciation model for this machine would be
For number of years, the cost of the machine would become
This is properly written as
where x represents the number of years.
For example, after 5 years, the value of the machine would become
The value of the machine would be $500 at the end of the fifth year.
From the above, the equation to show the depreciation at the end of x years is f(x) = 1500 - 200x
Learn more on linear equations here;
