How do you solve the following system: $5 x - 7 y = 12, x + 8 y = 15$ $5x - 7y = 12 , x + 8y = 15$ ?

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Answer 1 · 2016-05-21T11:35:43

The solution for the system of equations is:
$x = \frac{201}{47}, y = \frac{63}{47}$ $color(green)(x=201/47 , y = 63/47$

$5 x - 7 y = 12$ $color(blue)(5x) - 7y =12$ .............equation $(1)$ $(1)$

$x + 8 y = 15$ $x + 8y = 15$ , multiplying by $5$ $5$
$5 x + 40 y = 75$ $color(blue)(5x) + 40y = 75$ ..........equation $(2)$ $(2)$

Solving by elimination:

Subtracting equation $2$ $2$ from equation $1 :$ $1:$

$cancelcolor(blue)(5x) - 7y =12$
$-cancelcolor(blue)(5x) - 40y = -75$

$-47 y = -63$

$y = -63 / (47 )$

$color(green)(y = 63/47$

Finding $x$ from equation $2$
$x + 8y = 15$

$x = 15 - 8y$

$x = 15 - 8 * (63/47)$

$x = 15 - 504/47$

$x = 705 /47 - 504/47$

$color(green)(x = 201/47$

How do you solve the following system: 5x - 7y = 12 , x + 8y = 15 5x−7y=12,x+8y=155x - 7y = 12 , x + 8y = 15 ?