How do you solve the following system: $3 x + 4 y = - 10, x - 2 y = 4$ $3x+4y=-10, x-2y=4$ ?

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Answer 1 · 2016-01-08T17:10:01

The solution for the system of equations is
$x = - \frac{2}{5}, y = - \frac{11}{5}$ $color(blue)(x=-2/5, y=-11/5$

$3 x + 4 y = - 10$ $color(blue)(3x)+4y=-10$ ......equation $(1)$ $(1)$

$x - 2 y = 4$ $x -2y=4$ , multiplying by $3$ $3$
$3 x - 6 y = 12$ $color(blue)(3x) -6y=12$ .............equation $(2)$ $(2)$

Solving by elimination

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

$cancelcolor(blue)(3x)+4y=-10$
$-cancelcolor(blue)(3x) +6y=-12$

$10y =-22$

$y =-22/10$

$color(blue)(y =-11/5$

Finding $x$ from equation $2$
$x -2y=4$

$x =4 +2y$

$x =4 +2 xx(-11/5)$

$x =4 -22/5$

$x =20/5 -22/5$

$color(blue)(x= -2/5$

How do you solve the following system: 3x+4y=-10, x-2y=4 3x+4y=−10,x−2y=43x+4y=-10, x-2y=4 ?