Simultaneous Equation: 3x + y = -4 / 3x - 4y = 6
Route 1 (Standard): 1. 3x + y = -4 / 2. 3x - 4y = 6 / MINUS 2 FROM 1 / y - (-4y) = 5y / -4 - 6 = - 10 / 5y = - 10 / y = -2 /PUT y-VALUE BACK INTO ORIGINAL EQ / 3x - 2 = -4 / 3x = - 4 + 2 / 3x = -2 /x = - 2/3 Route 2 (Alternative): 1. 3x + y = -4 GOES TO y = -4 - 3x / 2. 3x - 4y = 6 GOES TO 3x = 6 + 4y / PUT 1 INTO 2/ 3x = 6 + 4(-4 -3x) / 3x = 6 -16 -12x / 3x + 12x = 6-16 / 15x = -10 / x = - 10/15 / x = - 2/3 / PUT x-VALUE BACK INTO 'y' EQ / y = -4 - (3*- 2/3) / y = -4 - (-2) / y = -4 + 2 / y = -2
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