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Question 250134: 5r-7s=-28
7r+5s=94
solve by the elimination method
the solution it says is an ordered pair
Can anyone help please?
Answer by richwmiller(17219)   (Show Source):
You can put this solution on YOUR website! an ordered pair means the two solutions are arranged (r,s)
5r-7s=-28
7r+5s=94
"by elimination" means that we combine the two equations in such a way that one of the terms ( r or s) is eliminated.
That can be by addition, subtraction, mulitplication or division of the two equations.
if we multiply the first by 5 and the second by 7 we can add them and eliminate s
5r-7s=-28
7r+5s=94
25r-35s=-28*5
49r+35s=94*7
add them
74r=-28*5+94*7
multiply out and add
then divide both sides by 74 to get r
then take that solved r and plug it into ANY of the equations to get s
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