Just need a quick question answered flood, in solving a linear equation by substitution are the variables always going to be equal to zero? Sometimes I see them go as one when solving, it always confuses me because I can't tell when to use zero or one. Or put it this way, is Y & X always equal to zero?
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Edited by HurtfulTurkey: 5/12/2013 3:39:55 AMNo... When given two or more equations with two or more variables, use on of the equations to find an equation for one of the variables, then plug that into another equation. x + b = 2 ...(1) 3x + 5b = 8 ...(2) Using (1), we see that x = 2 - b Plug that into (2), and you get: 3(2 - b) + 5b = 8 --> 6-3b + 5b = 8 --> 2b = 2 --> b = 1 Use that in equation (1), and you get: x + 1 = 2 --> x = 1 At no point are you setting variables equal to zero. If the variables happen to come out to be zero, it's just a coincidence. These can be solved easily with a matrix if you want to avoid doing it by hand.