Step-by-step explanation:
step 1. let l be the length of the rectangle
step 2. l = 2x + 4
step 3. lx = 390 yd^2
step 4. (2x + 4)x = 390
step 5. 2x^2 +4x = 390
step 6. 2x^2 + 4x - 390 = 0
step 7. -4 +- sqr(4^2 -4(2)(-390))/2(2) quadratic formula
step 8. (-4 +- sqr(3136))/4
step 9. (-4 +- 56)/4
step 10. x = 13yd, l = 2x + 4 = 2(13) + 4 = 30yd.
Answer:
X = 1
Step-by-step explanation:
subtract 14 from both sides
6x = 6
divide both sides by 7
X = 1
9514 1404 393
Answer:
1 +i√3.5
Step-by-step explanation:
In vertex form, the equation is ...
2(x² -2x +1) +7 = 0
2(x -1)² +7 = 0
Then the solutions are ...
(x -1)² = -7/2
x = 1 ±i√3.5
One solution is 1+i√3.5.
Answer:
Option C is correct.
Step-by-step explanation:
-x+3y=2
4x-2y=22
In matrix form is represented as:
![\left[\begin{array}{cc}-1&3\\4&-2\end{array}\right] \left[\begin{array}{c}x&y\end{array}\right] =\left[\begin{array}{c}2&22\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D-1%263%5C%5C4%26-2%5Cend%7Barray%7D%5Cright%5D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7Dx%26y%5Cend%7Barray%7D%5Cright%5D%20%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D2%2622%5Cend%7Barray%7D%5Cright%5D)
AX=B
|A| = (-1)(-2)-(3)(4)
|A| = 2-12
|A| = -10
Adj A = ![\left[\begin{array}{cc}-2&-3\\-4&-1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D-2%26-3%5C%5C-4%26-1%5Cend%7Barray%7D%5Cright%5D)
A^-1 = -1/10
A^-1 = 1/10![\left[\begin{array}{cc}2&3\\4&1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D2%263%5C%5C4%261%5Cend%7Barray%7D%5Cright%5D)
X= A^-1 B
X = 1/10![\left[\begin{array}{c}2&22\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D2%2622%5Cend%7Barray%7D%5Cright%5D)
X=1/10![X=1/10\left[\begin{array}{c}2*2+3*22\\4*2+1*22\end{array}\right]\\X=1/10\left[\begin{array}{c}4+66\\8+22\end{array}\right]\\X=1/10\left[\begin{array}{c}70\\30\end{array}\right]\\X=\left[\begin{array}{c}70/10\\30/10\end{array}\right]\\X=\left[\begin{array}{c}7\\3\end{array}\right]](https://tex.z-dn.net/?f=X%3D1%2F10%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D2%2A2%2B3%2A22%5C%5C4%2A2%2B1%2A22%5Cend%7Barray%7D%5Cright%5D%5C%5CX%3D1%2F10%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D4%2B66%5C%5C8%2B22%5Cend%7Barray%7D%5Cright%5D%5C%5CX%3D1%2F10%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D70%5C%5C30%5Cend%7Barray%7D%5Cright%5D%5C%5CX%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D70%2F10%5C%5C30%2F10%5Cend%7Barray%7D%5Cright%5D%5C%5CX%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D7%5C%5C3%5Cend%7Barray%7D%5Cright%5D)
So, x = 7 and y =3
Hence Option C is correct.
The answer is 10/3. Because you have 3 wholes and 1/3 so, 3x3 is 9 and you still have the extra 1 so 9+1=10 therefore your answer would be 10/3
