How do you solve $x - y = 3$ $x-y=3$ and $7 x - y = - 3$ $7x-y=-3$ using substitution?

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Answer 1 · 2016-05-07T21:28:32

$x = - 1 and y = - 4$ $x = -1 and y = -4$

Another method which will work well in this case is to equate two equal expressions. This is a form of substitution.

Transpose both equations to give $y = ...........$

equ 1. $y = x - 3" and "$ equ 2. $y = 7x + 3$

Note that $" " y = y$

Therefore: $7x + 3 = x - 3$
$" " 6x = -6$
$" "x = -1$

Equ 1. $y = -1 -3 rArr y = -4$

How do you solve x-y=3x−y=3x-y=3 and 7x-y=-37x−y=−37x-y=-3 using substitution?