You use the FOIL method, and how you do this is -
(x - 7) (x + 8)
Multiply the first x by both numbers in the second factor. Which means, you multiply x by x and 8, the two in (x + 8).
With this, you get -
x^2 + 8x
Then do the same thing with -7.
-7x - 56
Then combine the two.
x^2 + 8x - 7x - 56
Combine like terms.
x^2 + x - 56
So now, 7 x 8 is 56
And -7 + 8 would be 1. And that is the value of “x” which is b in the form a^2x + bx + c.
Now with this, you take those two numbers and make the factors =
(x + 8) (x - 7)
Then you set these equal to 0.
x + 8 = 0
Subtract the 8 from both sides.
x = -8
————
x - 7 = 0
Add the 7 on both sides.
x = 7
Answer: A
Answer:
y = 3/2x + 15
Step-by-step explanation:
change f(x) to 'y='
interchange 'x' and 'y' then solve for 'y':
y = 2/3x - 10
x = 2/3y - 10
x+10 = 2/3y
multiply each side by 3/2 to get:
y = 3/2x + 15
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.
Answer:
$2,323.2
Step-by-step explanation:
A = P(1 + r/n)^nt
Where,
A = future value = ?
P = present value = 2,000
r = interest rate = 5% = 0.05
n = number of periods = 12
t = time = 3 years
A = P(1 + r/n)^nt
= 2,000(1 + 0.05/12)^12*3
= 2,000( 1 + 0.00417)^36
= 2,000( 1.00417)^36
= 2,000(1.1616)
= 2,323.2
A = $2,323.2
Answer:
first one
Step-by-step explanation:
the sum of (9k-4) =3542
so it will be the first one because
28((5+248)/2)=3542
