Answer:
Step-by-step explanation:
x² + b²/4a² = -c / a + b²/4a²
x² + (b/2a)² = -c/a + (b/2a)²
(x + b/2a)² = -c/a + (b/2a)² = -c / a + b²/4a² = (-4ac+ b²)/4a²
(x + b/2a)² = (-4ac+ b²)/4a²
√{(x + b/2a)²} = √{(-4ac+ b²)/4a²}
x + b/2a = √(-4ac+ b²) / √(4a²) = √(-4ac+ b²) / 2a = √( b²-4ac) / 2a
x + b/2a = √( b²-4ac) / 2a
- subtract b/2a from both sides
x + b/2a -b/2a = {√( b²-4ac) / 2a } -b/2a
x = -b/2a + {√( b²-4ac) / 2a }
x = {-b±√( b²-4ac)}/2a
Given:
Annual salary average: $22,040
Annual Social security benefit: 42% of salary average
Monthly bill: $1,375
$22,040 x 42% = $9,256.80 per annum
$9,256.80 / 12 mos = $771.40 per month
$1,375 – 771.40 = $603.60
Since, Christina only receives $771.40 per month from her Social Security benefit, she has to take $603.60 from her savings each month to help pay her monthly bill of $1,375.
<span>
</span>
Answer:

And when we apply the limit we got that:

Step-by-step explanation:
Assuming this complete problem: "The following formula for the sum of the cubes of the first n integers is proved in Appendix E. Use it to evaluate the limit . 1^3+2^3+3^3+...+n^3=[n(n+1)/2]^2"
We have the following formula in order to find the sum of cubes:

We can express this formula like this:
![\lim_{n\to\infty} \sum_{n=1}^{\infty}i^3 =\lim_{n\to\infty} [\frac{n(n+1)}{2}]^2](https://tex.z-dn.net/?f=%20%5Clim_%7Bn%5Cto%5Cinfty%7D%20%5Csum_%7Bn%3D1%7D%5E%7B%5Cinfty%7Di%5E3%20%3D%5Clim_%7Bn%5Cto%5Cinfty%7D%20%5B%5Cfrac%7Bn%28n%2B1%29%7D%7B2%7D%5D%5E2)
And using this property we need to proof that: 1^3+2^3+3^3+...+n^3=[n(n+1)/2]^2
![\lim_{n\to\infty} [\frac{n(n+1)}{2}]^2](https://tex.z-dn.net/?f=%20%5Clim_%7Bn%5Cto%5Cinfty%7D%20%5B%5Cfrac%7Bn%28n%2B1%29%7D%7B2%7D%5D%5E2)
If we operate and we take out the 1/4 as a factor we got this:

We can cancel
and we got

We can reorder the terms like this:

We can do some algebra and we got:

We can solve the square and we got:

And when we apply the limit we got that:

Answer:

Step-by-step explanation:
we know that
If CD is parallel to XZ
then
Triangle XYZ is similar to Triangle YCD
therefore
The ratio of their corresponding sides are equal

we have
CX=5\ units, CY=25\ units, YD=20\ units,




substitute the values




Price before tax = $18
Tax = 7% x $18 = 0.07 x 18 = $1.26
Price after tax = $18 + $1.26 = $19.26
Answer: $19.26