How do you solve the following system: $9 x - 3 y = - 30, 4 x + 2 y = 0$ $9x - 3y = -30, 4x + 2y = 0$ ?

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Answer 1 · 2018-03-09T13:01:47

Arrange the equations. Get $x = - 2$ $x=-2$ and $y = 4$ $y=4$

Expand the first equation with 2 and the second equation with 3:

$18 x - 6 y = - 60$ $18x - 6y = -60$
$12 x + 6 y = 0$ $12x + 6y = 0$

Sum these up:

$30 x = - 60$ $30 x = -60$

$x = - 2$ $x=-2$

Now you can compute the value of y (I use the second original equation to find the value of y):

$(4 \times - 2) + 2 y = 0$ $(4times-2) + 2y= 0$

$2 y = 8$ $2y = 8$

$y = 4$ $y=4$

How do you solve the following system: 9x - 3y = -30, 4x + 2y = 0 9x−3y=−30,4x+2y=09x - 3y = -30, 4x + 2y = 0 ?