How do you solve the following system: $10y=42+2x , y= 3/4x+3$ ?

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Answer 1 · 2016-04-06T06:46:35

$x=24/11$
$y=51/11$

$10y=42+2x" (1)"$

$"expand the second equation by 10"$

$y=3/4x+3" (2)"$

$color(red)10*y=color(red)10*(3/4x+3)$

$10y=30/4x+30" (3)"$

$"so left side of the equations (1) and (3)are equal"$

$"we can write:"$

$42+2x=30/4x+30$

$2x-30x/4=30-42$

$(8x-30x)/4=-12$
$-22x=-4*12$

$22x=48" "x=48/22$
$x=24/11$

$" now use the equation (1)"$

$10y=42+2(24/11)$

$10y=42+48/11$

$10y=(462+48)/11$

$y=(51cancel(0))/(11cancel(0))$

$y=51/11$

How do you solve the following system: 10y=42+2x , y= 3/4x+3 10y=42+2x , y= 3/4x+3 ?