How do you solve $y = - 3 x + 5$ $y = -3x + 5$ and $5 x - 4 y = - 3$ $5x - 4y = -3$ using substitution?

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Answer 1 · 2016-03-13T23:23:39

$x = 1$ $x=1$
$y = 2$ $y=2$

$1$ $1$ . Start by labelling the equations.

Equation $1$ $1$ : $y = - 3 x + 5$ $color(orange)(y=-3x+5)$

Equation $2$ $2$ : $5 x - 4 y = - 3$ $color(blue)(5x-4y=-3)$

$2$ $2$ . Substitute equation $1$ $1$ into equation $2$ $2$ .

$5 x - 4 y = - 3$ $color(blue)(5x-4y=-3)$

$5 x - 4 (- 3 x + 5) = - 3$ $color(blue)(5x-4color(orange)((-3x+5))=-3)$

$3$ $3$ . Solve for $x$ $x$ .

$5 x + 12 x - 20 = - 3$ $5x+12x-20=-3$

$17 x = 17$ $17x=17$

$color(green)(|bar(ul(color(white)(a/a)x=1color(white)(a/a)|)))$

$4$ . Substitute $color(red)(x=1)$ into equation $1$ to find the value of $y$ .

$color(orange)(y=-3x+5)$

$color(orange)(y=-3color(red)((1))+5)$

$5$ . Solve.

$y=-3+5$

$color(green)(|bar(ul(color(white)(a/a)y=2color(white)(a/a)|)))$

$:.$ , $x$ is $1$ and $y$ is $2$ .

How do you solve y = -3x + 5y=−3x+5 y = -3x + 5 and 5x - 4y = -35x−4y=−35x - 4y = -3 using substitution?