Answer:
x = 3 ±
Step-by-step explanation:
x² - 6x - 4 = 0 ( add 4 to both sides )
x² - 6x = 4
To complete the square
add ( half the coefficient of the x- term)² to both sides
x² + 2(- 3)x + 9 = 4 + 9
(x - 3)² = 13 ( take square root of both sides )
x - 3 = ± ( add 3 to both sides )
x = 3 ±
The formula for depreciation is:
Where x = Initial value,
y= Amount after depreciation.
r= Rate of depreciation,
t = time (in years)
According to given problem,
x = 1040, y= 944 and t = 12 months =1 year.
So, first step is to plug in these values in the above formula, So,
944 = 1040 (1 -r)
Divide each sides by 1040.
0.907692308 =1 - r
0.907692308 - 1 = -r Subtract 1 from each sides.
-0.092307692 = -r
So, r = 0.09 or 9%.
Now plug in 0.09 in the above equation to get the depreciation equation. So,
So,
b) To find the value of the bike after 5 months,
plug in t = 5 months= 5/12 = 0.41667 years in the above equation of depreciation.
So,
y = 1040 * 0.961465659
y = 999.9242852
y = 1000 (Rounded to nearest integer).
Hence, the value of the bike after 5 months is $1000.
