Answer:
C: y+7=2/5(x+4)
Step-by-step explanation:
The point-slope form of the equation of a line with slope m through point (h, k) is ...
y -k = m(x -h)
You are given m=2/5 and (h, k) = (-4, -7). Put these numbers into the form and simplify the signs:
y -(-7) = 2/5(x -(-4)) . . . . . numbers put into the form
y +7 = 2/5(x +4) . . . . . . . signs simplified . . . . matches choice C
We want to find the values of a, b, c, and d such that the given matrix product is equal to a 2x2 identity matrix. We will solve a system of equations to find:
<h3>
Presenting the equation:</h3>
Basically, we want to solve:
![\left[\begin{array}{cc}-1&2\\a&1\end{array}\right]*\left[\begin{array}{cc}b&c\\1&d\end{array}\right] = \left[\begin{array}{cc}1&0\\0&1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D-1%262%5C%5Ca%261%5Cend%7Barray%7D%5Cright%5D%2A%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7Db%26c%5C%5C1%26d%5Cend%7Barray%7D%5Cright%5D%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D1%260%5C%5C0%261%5Cend%7Barray%7D%5Cright%5D)
The matrix product will be:
![\left[\begin{array}{cc}-b + 2&-c + 2d\\a*b + 1&a*c + d\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D-b%20%2B%202%26-c%20%2B%202d%5C%5Ca%2Ab%20%2B%201%26a%2Ac%20%2B%20d%5Cend%7Barray%7D%5Cright%5D)
Then we must have:
-b + 2 = 1
This means that:
b = 2 - 1 = 1
We also need to have:
a*b + 1 = 0
we know the value of b, so we just have:
a*1 + b = 0
Now the two remaining equations are:
-c + 2d = 0
a*c + d = 1
Replacing the value of a we get:
-c + 2d = 0
-c + d = 1
Isolating c in the first equation we get:
c = 2d
Replacing that in the other equation we get:
-(2d) + d = 1
-d = 1
Then:
c = 2d = 2*(-1) = -2
So the values are:
If you want to learn more about systems of equations, you can read:
brainly.com/question/13729904
MMMLXXXIX
~ hope this helps!
Answer:
Step-by-step explanation:
A)
these are the intervals of people who are at least adults and are mature enough to take the survey seriously and answer correctly.
B)
You can say with 95 percent certain of the real mean of the population, but you acknowledge that due to difficulties such as, sampling error, real-life problems such as bad weather, bad vision of the surveyed, not knowing the language and due to bad wording, your answers are unsure is the range of 8 percent due the fluctuation of data caused by bad circumstances.
C)
I believe there should be a quota of 50 to 50 percent to make the data the most equal, though I understand that there may not be an equal distribution of land and cell lines among the U.S. mature populace.
D)
(Since I don't have the data, I can't answer part 4)
Answer:
x = 80°
Step-by-step explanation:
Angle on a straight line = 180°
(x + 40)° + (x - 20)° = 180°
x + 40° + x - 20° = 180°
2x + 20° = 180°
2x = 180° - 20°
2x = 160°
x = 160°/2
x = 80°
Check:
(x + 40)° + (x - 20)° = 180°
(80° + 40°) + (80° - 20°) = 180°
120° + 60° = 180°
180° = 180°
