How do you solve by substitution $y = 2 x + 4$ $y = 2x + 4$ and $y = 3 x$ $y = 3x$ ?

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Answer 1 · 2015-06-10T19:54:57

$x = 4$ $x=4$
$y = 12$ $y=12$

$y = 3 x$ $y=3x$ is already solved for $y$ $y$ . Substitute it into the other equation.

$y = 2 x + 4$ $y=2x+4$ =

Substitute $3 x$ $3x$ for $y$ $y$ and solve for $x$ $x$ .

$3 x = 2 x + 4$ $3x=2x+4$ =

$x = 4$ $x=4$

Substitute $4$ $4$ for $x$ $x$ in the equation $y = 3 x$ $y=3x$ .

$y = 3 (4)$ $y=3(4)$ =

$y = 12$ $y=12$

Check by substituting the values for $x$ $x$ and $y$ $y$ into both equations.

First equation.

$y = 2 x + 4$ $y=2x+4$ =

$12 = 2 (4) + 4$ $12=2(4)+4$ =

$12 = 12$ $12=12$ Check.

Second equation.

$y = 3 x$ $y=3x$ =

$12 = 3 (4)$ $12=3(4)$ =

$12 = 12$ $12=12$ Check.

How do you solve by substitution y = 2x + 4y=2x+4y = 2x + 4 and y = 3x y=3xy = 3x ?