Let's use Gaussian elimination. Consider the augmented matrix,
![\left[\begin{array}{ccc|ccc}1 & -1 & -1 & 1 & 0 & 0\\-1 & 2 & 3 & 0 & 1 & 0\\1 & 1 & 4 & 0 & 0 & 1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cccc%7D1%20%26%20-1%20%26%20-1%20%26%201%20%26%200%20%26%200%5C%5C-1%20%26%202%20%26%203%20%26%200%20%26%201%20%26%200%5C%5C1%20%26%201%20%26%204%20%26%200%20%26%200%20%26%201%5Cend%7Barray%7D%5Cright%5D)
• Add row 1 to row 2, and add -1 (row 1) to row 3:
![\left[\begin{array}{ccc|ccc}1 & -1 & -1 & 1 & 0 & 0\\0 & 1 & 2 & 1 & 1 & 0\\0 & 2 & 5 & -1 & 0 & 1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cccc%7D1%20%26%20-1%20%26%20-1%20%26%201%20%26%200%20%26%200%5C%5C0%20%26%201%20%26%202%20%26%201%20%26%201%20%26%200%5C%5C0%20%26%202%20%26%205%20%26%20-1%20%26%200%20%26%201%5Cend%7Barray%7D%5Cright%5D)
• Add -2 (row 2) to row 3:
![\left[\begin{array}{ccc|ccc}1 & -1 & -1 & 1 & 0 & 0\\0 & 1 & 2 & 1 & 1 & 0\\0 & 0 & 1 & -3 & -2 & 1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cccc%7D1%20%26%20-1%20%26%20-1%20%26%201%20%26%200%20%26%200%5C%5C0%20%26%201%20%26%202%20%26%201%20%26%201%20%26%200%5C%5C0%20%26%200%20%26%201%20%26%20-3%20%26%20-2%20%26%201%5Cend%7Barray%7D%5Cright%5D)
• Add -2 (row 3) to row 2:
![\left[\begin{array}{ccc|ccc}1 & -1 & -1 & 1 & 0 & 0\\0 & 1 & 0 & 7 & 5 & -2\\0 & 0 & 1 & -3 & -2 & 1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cccc%7D1%20%26%20-1%20%26%20-1%20%26%201%20%26%200%20%26%200%5C%5C0%20%26%201%20%26%200%20%26%207%20%26%205%20%26%20-2%5C%5C0%20%26%200%20%26%201%20%26%20-3%20%26%20-2%20%26%201%5Cend%7Barray%7D%5Cright%5D)
• Add row 2 and row 3 to row 1:
![\left[\begin{array}{ccc|ccc}1 & 0 & 0 & 5 & 3 & -1\\0 & 1 & 0 & 7 & 5 & -2\\0 & 0 & 1 & -3 & -2 & 1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cccc%7D1%20%26%200%20%26%200%20%26%205%20%26%203%20%26%20-1%5C%5C0%20%26%201%20%26%200%20%26%207%20%26%205%20%26%20-2%5C%5C0%20%26%200%20%26%201%20%26%20-3%20%26%20-2%20%26%201%5Cend%7Barray%7D%5Cright%5D)
So the inverse is

<h3>
Answer: Negative</h3>
======================================================
Explanation:
3/7 = 0.42857 approximately
Pick a number between that value and 5, not including either endpoint. Let's say we pick x = 2
Plug x = 2 into the f(x) function
f(x) = (x - 5)(2x + 7)(7x-3)
f(2) = (2 - 5)(2*2 + 7)(7*2-3)
f(2) = (2 - 5)(4 + 7)(14-3)
f(2) = (-3)(11)(11)
f(2) = -363
The actual result doesn't matter. All we're after is whether the result is positive or negative. We see the result is negative. This means f(x) is negative when 3/7 < x < 5. The f(x) curve is below the x axis on this interval.
Answer:
y= 
Step-by-step explanation:
To find inverse of something, just switch the variables
x=y^2
now try to solve back in terms of y
y= 
Answer:
y=2/3x+4.3
Step-by-step explanation:
y=mx+c
(5-3)/(1--2)
2/3= gradient
y=2/3x +c
5=2/3(1)+c
-2/3
4.3=c