How do you solve $3y=-2x, y=x-5$ by substitution?

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Answer 1 · 2016-12-06T23:42:33

$x = 3$ and $y = -2$

Step 1) Because the second equation is already solved for $y$ we can substitute $x - 5$ for $y$ in the first equation and solve for $x$ :

$3(x - 5) = -2x$

$3x - 15 = -2x$

$3x - 15 + 15 + 2x = -2x + 15 + 2x$

$3x - 0 + 2x = 0 +15$

$5x = 15$

$(5x)/5 = 15/5$

$x = 3$

Step 2) Substitute $3$ for $x$ in the second equation and calculate $y$ :

$y = 3 - 5$

$y = -2$