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

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Answer 1 · 2015-12-24T20:47:19

$(-12/7, -3/7)$

You can solve this system of equation by substitution

$color(red)(y = 2x +3$
$x + 3y = -3$

Substitute $y =2x + 3$ into the second equation

$x+ 3(color(red)(2x+3)) = -3$

Distribute and combine like terms

$x + 6x + 9 = -3$

$7x + 9 = -3$
$7x = -3 -9$

$7x = -12$

$x = -12/7$

Then re-substitute $x = -12/7$ into $y= 2x+3$ to solve for $y$

$y = 2( -12/7) + 3$
$=> y = -24/7 + 21/7$
$=> y = -3/7$

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