To see if (7,-5) is a solution to the system of equations then you have to plug them in.
We can make life simpler by first simplifying the equations then plugging (7,-5) into the equations. You must plug them into both to completely make sure.
2x-y = 19 (solving for y)
1. Subtract 2x from both sides.
-y = 19-2x
2. Divide both sides by -1.
y = -19+2x
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4x+3y = 13
1. Subtract 4x from both sides.
3y = 13-4x
2. Divide both sides by 3.
y = 13/3-4/3x
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Now go ahead and plug them in to the newly simplified equations. Start with the first equation (y = -19+2x).
(7,-5) => -5 = -19+2(7)
-5 = -19+(14)
-5 = (-5), this is TRUE so that means so far (7,-5) is a possible solution. Moving on to the next equation (y = 13/3-4/3x).
(7,-5) => -5 = 13/3-4/3(7)
-5 = 13/3-28/3
-5 = -15/3
-5 = -5, this is also TRUE so that means that (7,-5) IS a solution to this system of equations.
Answer is:
A. Yes
