Question 722929:  Is (8, -1) a solution of the system, 2x + 3y = 13 and x - y = 9? 
 Found 2 solutions by  jim_thompson5910, DrBeeee: Answer by jim_thompson5910(35256)      (Show Source): 
You can  put this solution on YOUR website! 2x + 3y = 13
 
 
2(8) + 3(-1) = 13 ... plug in (8,1)
 
 
16 - 3 = 13
 
 
13 = 13
 
 
so (8,1) satisfies the first equation
 
 
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x - y = 9
 
 
8 - (-1) = 9 ... plug in (8,1)
 
 
8 + 1 = 9
 
 
9 = 9
 
 
and (8,1) satisfies the second equation
 
 
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(8,1) satisfies BOTH equations at the same time, so it is the solution to the system of equations 
 Answer by DrBeeee(684)      (Show Source): 
You can  put this solution on YOUR website! Put (x,y) = (8,-1) into the two equations and check. 
Is (2*8+3*(-1) = 13)? 
Is (16 - 3 = 13)? 
Is (13 = 13)? Yes 
Is (8 -(-1) = 9)? 
Is (9 = 9)? Yes 
Answer: Yes, (8,-1) is the solution (and only solution) to the given system of equations. 
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