How do you solve $y=3x+2$ and $y=4/3x-5$ using substitution?

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Answer 1 · 2016-12-23T07:19:50

$x=-4 1/5$ and $y=-10 3/5$

$y=3x+2$
$y=4/3x-5$

In the second equation, substitute $y$ with $color(red)((3x+2))$ . This equivalence is taken from the first equation.

$color(red)(3x+2)=4/3x-5$

Multiply all terms by $3$ .

$9x+6=4x-15$

Subtract $4x$ from each side.

$5x+6=-15$

Subtract $6$ from each side.

$5x=-21$

Divide both sides by $5$ .

$x=-21/5$ or $x=-4 1/5$

In the first equation, substitute $x$ with $color(blue)(-21/5)$ .

$y=3x+2$

$y=3color(blue)((-21/5))+2$

$y=-63/5+2$

$y=(-63+10)/5$

$y=-53/5$ or $y=-10 3/5$

How do you solve y=3x+2y=3x+2 and y=4/3x-5y=4/3x-5 using substitution?