Answer:
- x = -1/2(1 +√21) ≈ -2.79129
- x = -1/2(1 -√21) ≈ 1.79129
Step-by-step explanation:
We assume the middle term is supposed to be 4x.
We can remove a common factor of 4 to simplify this a bit.
x^2 +x -5 = 0
This is of the form
ax^2 +bx +c = 0
where a=1, b=1, c=-5.
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The <em>quadratic formula</em> gives the solutions as ...
Filling in the given coefficients, we have ...
x = (-1 ±√(1^2 -4·1·(-5)))/(2·1)
x = (-1±√21)/2
The solutions are x = -1/2(1 +√21) and -1/2(1 -√21).
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<em>If what you wrote is what you intend</em>, then the equation simplifies to 4x^2 -16 = 0.
Dividing by 4 and factoring the difference of squares gives ...
x^2 -4 = 0
(x -2)(x +2) = 0
These factors are zero (hence their product is 0) for the values x = 2 and x = -2.
The solutions are x=2 and x=-2.
58
Between 60 and 55, 5+8=13
Answer:
$12/25 pencils= $0.48 per pencil
I'll do the first two problems to get you started. All problems shown will use the same formula.
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Problem 4
The formula to use is
C = 100*(B-A)/A
where
A = old value
B = new value
C = percent change
In this case, A = 12 and B = 36, so
C = 100*(B-A)/A
C = 100*(36-12)/12
C = 100*(24/12)
C = 100*2
C = 200%
We have a 200% increase. It is an increase because the value of C is positive.
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Problem 5
Use the same formula as in the previous problem. This time,
A = 75 is the old value
B = 25 is the new value
C = 100*(B-A)/A
C = 100*(25-75)/75
C = 100*(-50/75)
C = 100*(-2/3)
C = -66.6667%
C = -66.7%
The value of C is negative, so we have a percent decrease of roughly 66.7%
Answer:
You're answer is 42
Step-by-step explanation:
if you add all the numbers together, you would get 336. since there are eight numbers in the data set, you should divide it by eight.. with that said, 336/8 is 42