As it's name suggests, when we solve by substitution, we substitute the expression for one variable in one equation for that variable in the other equation. from the second equation, we see that y = x + 2, so we simply substitute x + 2 for y in the other eqaution. we would then have an equation with only x, which is easy to solve.
no, elimination is a different concept. here we try to ELIMINATE one variable from one of our equations by adding or subtracting the two equations. Sometimes we may have to multiply one or both equations by a constant so we can eliminate a variable. here we see that we have a y in one equation and a -y in the other. if we add the two equations then, we would get rid of the y, since y + (-y) = 0y
Can you tell me what is?
Originally Posted by volcombro2000
Last edited by ThePerfectHacker; Jun 2nd 2007 at 06:24 PM.