The matrix represents the system:
-3x+5y=15
2x+3y=-10, which is choice c. 
We can see it more clearly from the way we multiply matrices, as follows:
![\[
  \left[ {\begin{array}{cc}
   -3 & 5 \\
    \ 2  & 3 \\
  \end{array} } \right]
\] \cdot  \[
  \left[ {\begin{array}{c}
   x \\
    y \\
  \end{array} } \right]
\]= \left[ {\begin{array}{c}
   -3\cdot x+5\cdot y \\
    2\cdot x+3\cdot y \\
  \end{array} } \right]
\]= \[ \left[ {\begin{array}{c} 15 \\ -10 \\ \end{array} } \right] \]](https://tex.z-dn.net/?f=%20%5C%5B%0A%20%20%5Cleft%5B%20%7B%5Cbegin%7Barray%7D%7Bcc%7D%0A%20%20%20-3%20%26%205%20%5C%5C%0A%20%20%20%20%5C%202%20%20%26%203%20%5C%5C%0A%20%20%5Cend%7Barray%7D%20%7D%20%5Cright%5D%0A%5C%5D%20%5Ccdot%20%20%5C%5B%0A%20%20%5Cleft%5B%20%7B%5Cbegin%7Barray%7D%7Bc%7D%0A%20%20%20x%20%5C%5C%0A%20%20%20%20y%20%5C%5C%0A%20%20%5Cend%7Barray%7D%20%7D%20%5Cright%5D%0A%5C%5D%3D%20%5Cleft%5B%20%7B%5Cbegin%7Barray%7D%7Bc%7D%0A%20%20%20-3%5Ccdot%20x%2B5%5Ccdot%20y%20%5C%5C%0A%20%20%20%202%5Ccdot%20x%2B3%5Ccdot%20y%20%5C%5C%0A%20%20%5Cend%7Barray%7D%20%7D%20%5Cright%5D%0A%5C%5D%3D%20%5C%5B%20%5Cleft%5B%20%7B%5Cbegin%7Barray%7D%7Bc%7D%2015%20%5C%5C%20-10%20%5C%5C%20%5Cend%7Barray%7D%20%7D%20%5Cright%5D%20%5C%5D)
Answer: C
 
        
        
        
Answer:
   x = -7
Step-by-step explanation:
Subtract 15 from both sides of the equation.
   x = 8 -15 = -7
 
        
             
        
        
        
Bulletin boards can be in all shapes and sizes. There is no correct or incorrect answer to this problem. 
        
                    
             
        
        
        
Answer:
Equation ---->    2(c - 40)
c = -40
Step-by-step explanation:
2(c - 40)
= (2c) - (80)
= 2c - 80
=  +
 + 
c = -40
 
        
                    
             
        
        
        
Answer:
c=72
Step-by-step explanation:
8
=
9
8
⋅
8
=
8
⋅
9