Answer:
x= -2-√11. or. x= -2 + √11
Step-by-step explanation:
solving quadratic equation by completing the square
x^2+4x-7=0
x^2+4x=7
x^2+4x + (4/2)^2=7 + (4/2)^2 ( adding (1/2 coefficient of x)^2 on both sides
x^2+4x + 4=7 + 4
x^2+4x + 4=11. factorize(x^2+4x + 4) into (x + 2)^2
(x + 2)^2=11
√(x + 2)^2= + - √11
x + 2 = + - √11
there are two different solution .
x + 2 = -√11. or x + 2 = + √11.
x= -2-√11. or. x= -2 + √11.
A) Now look, in the year 2000, the population is 118,000
In the year 2006 is 138,000
To find the percent change |Original Amt - New Amt| -------------------------------- x100
Original Amt
So for this question you would do 118,00 - 138,000 (ignore the negativesss)
and you get -20,000 (ignore the negatives) and then you get 20,000
Now, you have to do 20,000 divided by 118,000 x 100
20,000 divided by 118,000 and you get 0.169491525
Now you have to multiply 0.169491525 by 100
0.169491525 x 100 = 16.9491525
Round this and you get a 16.9% change.
b) To predict the population in 2012 you will have to do 138,000 + 16.9%
To calculate this you have to do this:
138,000 x 0.169 = 23322
Now add 23,322, to 138,000 and you get 161,322.
A) 16.9%
B) 161,322
hope this helped :)
Answer:
I think b
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Answer:
B) (4x-5i)(4x+5i)
Step-by-step explanation:
The expression can be treated as the difference of squares, and factored accordingly. That factoring is ...
a² -b² = (a -b)(a +b)
__
Here, we have ...
a² -b² = 16x² -(-25)
a² = 16x² ⇒ a = 4x
b² = -25 ⇒ b = √-25 = 5i
Then the factoring is ...
(a -b)(a +b) = (4x -5i)(4x +5i)