Solve? $2 x - 10 y = - 20 and - x + 4 y = 28$ $2x-10y=-20 and -x+4y=28$

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Answer 1 · 2017-04-25T13:58:51

$10 y = 2 x + 20$ $10y=2x+20$ and $4 y = x + 28$ $4y=x+28$ .

Yielding, $x = - 100$ $x=-100$ and $y = - 18$ $y=-18$

Now multiply the second equation (by $- 2$ $-2$ ) and add equations:

$10 y = + 2 x + 20$ $" "10y=+2x+20$
$" "ul(-8y=-2x-56$
$" "2y=" "-36" "$ there is only $y$

Therefore $y=-18$

Now you can calculate $x$ by using either (original) equation
I have chosen the 2nd original equation.

$-x-72=28$

$-x=100$ . In other words,

$x=-100$

Your answer: $x=-100$ and $y=-18$

Answer 2 · 2017-04-25T14:10:24

I got:
$x=-100$
$y=-18$

I tryed multiplying the second equation by $2$ and adding to the first:
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Solve? 2x-10y=-20 and -x+4y=282x−10y=−20and−x+4y=282x-10y=-20 and -x+4y=28