How do you solve $x - 5 y = - 2$ $x-5y=-2$ and $- 7 x - 4 y = 14$ $-7x-4y=14$ using substitution?

Question

1436 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-05-05T13:31:33

$x = - 2$ $x=-2$
$y = 0$ $y=0$

$x - 5 y = - 2$ $x-5y=-2$ --- (1)
$- 7 x - 4 y = 14$ $-7x-4y=14$ --- (2)

From (1),

$x - 5 y = - 2$ $x-5y=-2$
$x = 5 y - 2$ $x=5y-2$ --- (3)

Sub (3) into (2)

$- 7 (5 y - 2) - 4 y = 14$ $-7(5y-2)-4y=14$
$- 35 y + 14 - 4 y = 14$ $-35y+14-4y=14$
$- 39 y = 0$ $-39y=0$
$y = 0$ $y=0$ --- (4)

Sub (4) into (3)
$x = 5 y - 2$ $x=5y-2$
$x = 0 - 2$ $x=0-2$
$x = - 2$ $x=-2$

How do you solve x−5y=−2x-5y=-2 and −7x−4y=14-7x-4y=14 using substitution?