y = 2x - 6

x^2 - xy + 2y^2 = 16

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- March 23rd 2008, 10:55 PMscarybear12Simultaneous Equation
y = 2x - 6

x^2 - xy + 2y^2 = 16 - March 23rd 2008, 11:08 PMo_O
You are given y in terms of x, so directly substitute:

Continue and solve for x. - March 24th 2008, 12:48 AMa.a
y = 2x - 6

x^2 - xy + 2y^2 = 16

=> x^2 - x (2x-6) + 2(2x-6)^2 = 16

x^2 - 2 x^2 + 6x + 2( 4x^2 -12x + 36) = 16

-x^2 + 6x + 8x^2 -24x + 72 -16 = 0

7x^2 - 18x + 56=0

use the quadraic eqn. to solve for x, then when u get the two x values, plug it into y = 2x - 6 and u the two y values - March 24th 2008, 06:39 AMo_O