Answer:
Step-by-step explanation:
To start take the equation and then plug in 9 for x
3x+4y=43
3(9)+4y=43
27+4y=43
Subtract 27 from each side to get all of the y's by themselves
27+4y-27=43-27
4y=16
Divide by four to get the value of one y
4y/4=16/4
y=4
Answer: c
<u>Step-by-step explanation:</u>
When multiplying matrices, multiply ACROSS with the left matrix and DOWN with the right matrix.
![\text{Example}:\left[\begin{array}{cc}a&b\\c&d\end{array}\right] \times \left[\begin{array}{c}x\\y\end{array}\right] =\left[\begin{array}{c}ax+by\\cx+dy\\\end{array}\right]](https://tex.z-dn.net/?f=%5Ctext%7BExample%7D%3A%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7Da%26b%5C%5Cc%26d%5Cend%7Barray%7D%5Cright%5D%20%5Ctimes%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7Dx%5C%5Cy%5Cend%7Barray%7D%5Cright%5D%20%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7Dax%2Bby%5C%5Ccx%2Bdy%5C%5C%5Cend%7Barray%7D%5Cright%5D)
![\left[\begin{array}{cc}5&2\\3&-1\end{array}\right] \times \left[\begin{array}{c}2\\3\end{array}\right] =\left[\begin{array}{c}5(2)+2(3)\\3(2)-1(3)\\\end{array}\right] = \left[\begin{array}{c}16\\3\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D5%262%5C%5C3%26-1%5Cend%7Barray%7D%5Cright%5D%20%5Ctimes%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D2%5C%5C3%5Cend%7Barray%7D%5Cright%5D%20%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D5%282%29%2B2%283%29%5C%5C3%282%29-1%283%29%5C%5C%5Cend%7Barray%7D%5Cright%5D%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D16%5C%5C3%5Cend%7Barray%7D%5Cright%5D)
number of accurate weather forecast over total number of days
21/36 to percentage is 58.33%
hence, 58.33% is the probability that the forecast tomorrow will be accurate.