PROBLEM: 4x + 8y = 20
-4x + 2y = -30
Answer:
4x and -4x get canceled &, so now you have
8y = 20
2y = -30
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10y = -10 <==== ADD the y's & solve for Y
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10 10
y = -1
Choose any of the two given equations n the problem(I chose equation #1) & solve for X!
4x + 8y = 20 <=== ORIONAL EQUATION
4x + 8 (-1) = 20 <=== Substitution
4x -8 = 20
+8 +8 <=== Add 8
4x = 28 <== Solve for X
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4 4
X = 7
(7, -1)