Take the augmented matrix,
![\left[\begin{array}{ccc|c}2&1&-3&-20\\1&2&1&-3\\1&-1&5&19\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cc%7D2%261%26-3%26-20%5C%5C1%262%261%26-3%5C%5C1%26-1%265%2619%5Cend%7Barray%7D%5Cright%5D)
Swap the row 1 and row 2:
![\left[\begin{array}{ccc|c}1&2&1&-3\\2&1&-3&-20\\1&-1&5&19\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cc%7D1%262%261%26-3%5C%5C2%261%26-3%26-20%5C%5C1%26-1%265%2619%5Cend%7Barray%7D%5Cright%5D)
Add -2(row 1) to row 2, and -1(row 1) to row 3:
![\left[\begin{array}{ccc|c}1&2&1&-3\\0&-3&-5&-14\\0&-3&4&22\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cc%7D1%262%261%26-3%5C%5C0%26-3%26-5%26-14%5C%5C0%26-3%264%2622%5Cend%7Barray%7D%5Cright%5D)
Add -1(row 2) to row 3:
![\left[\begin{array}{ccc|c}1&2&1&-3\\0&-3&-5&-14\\0&0&9&36\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cc%7D1%262%261%26-3%5C%5C0%26-3%26-5%26-14%5C%5C0%260%269%2636%5Cend%7Barray%7D%5Cright%5D)
Multiply through row 3 by 1/9:
![\left[\begin{array}{ccc|c}1&2&1&-3\\0&-3&-5&-14\\0&0&1&4\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cc%7D1%262%261%26-3%5C%5C0%26-3%26-5%26-14%5C%5C0%260%261%264%5Cend%7Barray%7D%5Cright%5D)
Add 5(row 3) to row 2:
![\left[\begin{array}{ccc|c}1&2&1&-3\\0&-3&0&6\\0&0&1&4\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cc%7D1%262%261%26-3%5C%5C0%26-3%260%266%5C%5C0%260%261%264%5Cend%7Barray%7D%5Cright%5D)
Multiply through row 2 by -1/3:
![\left[\begin{array}{ccc|c}1&2&1&-3\\0&1&0&-2\\0&0&1&4\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cc%7D1%262%261%26-3%5C%5C0%261%260%26-2%5C%5C0%260%261%264%5Cend%7Barray%7D%5Cright%5D)
Add -2(row 2) and -1(row 3) to row 1:
![\left[\begin{array}{ccc|c}1&0&0&-3\\0&1&0&-2\\0&0&1&4\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cc%7D1%260%260%26-3%5C%5C0%261%260%26-2%5C%5C0%260%261%264%5Cend%7Barray%7D%5Cright%5D)
So we have
.
Answer:
0.01470588235
Step-by-step explanation:
x is 
Step-by-step explanation:
Let us revise some rules of exponents
∵ 
- Factorize 27 and 9
∵ 27 = 3 × 3 × 3
∴ 27 = 3³
∵ 9 = 3 × 3
∴ 9 = 3²
Substitute them in the equation
∴ 
- Use the third rule to simplify each side
∴ 
- Use the fourth rule
∵ The bases of the two sides are equal
∴ Their exponents are equal
∴ 3x - 3 = 6x - 14
- Subtract 6x from both sides
∴ -3x - 3 = -14
- Add 3 to both sides
∴ -3x = -11
Divide both sides by -3
∴ x = 
x is 
Learn more:
You can learn more about equations in brainly.com/question/4934417
#LearnwithBrainly
The question is asking you to find the axis of symmetry, which is the x-value of the vertex. In order to do that you need to factor the function to find the zeros and add the zeros together and divide by two to find the axis of symmetry.
y=-16x^2+608x
y=-16x(x-38)
Zeros: x=0 and x=38
38/2=19
Therefore it takes 19 seconds for the projectile to reach its maximum height.
Hope this helps!
The percentage of the semicircle shaded section is approximately 23,606 %.
The percentage of the area of the semicircle is equal to the ratio of the semicircle area minus the half-cross area to the semicircle area. In other words, we have the following expression:

(1)
Where:
- Area of the half cross, in square centimeters.
- Area of the semicircle, in square centimeters.
- Percentage of the shaded section of the semicircle.
And the percentage of the shaded section is:
![r = \left[1-\frac{4 \cdot (2\,cm)^{2}+4\cdot \left(\frac{1}{2} \right)\cdot (2\,cm)^{2}}{0.5\cdot \pi\cdot (16\,cm^{2}+4\,cm^{2})} \right]\times 100](https://tex.z-dn.net/?f=r%20%3D%20%5Cleft%5B1-%5Cfrac%7B4%20%5Ccdot%20%282%5C%2Ccm%29%5E%7B2%7D%2B4%5Ccdot%20%5Cleft%28%5Cfrac%7B1%7D%7B2%7D%20%5Cright%29%5Ccdot%20%282%5C%2Ccm%29%5E%7B2%7D%7D%7B0.5%5Ccdot%20%5Cpi%5Ccdot%20%2816%5C%2Ccm%5E%7B2%7D%2B4%5C%2Ccm%5E%7B2%7D%29%7D%20%5Cright%5D%5Ctimes%20100)

The percentage of the semicircle shaded section is approximately 23,606 %.
We kindly invite to check this question on percentages: brainly.com/question/15469506