How do you solve the system $4 x = 3 y + 31$ $4x=3y+31$ and $y = 2 x + 7$ $y=2x+7$ by substitution?

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Answer 1 · 2018-05-24T04:54:29

$(- 26, - 45)$ $(-26,-45)$

$4 x = 3 y + 31$ $4x= 3y+31$ -------(1)
$y = 2 x + 7$ $y=2x+7$ ----------(2)

Put (2) in (1),

$4 x = 3 (2 x + 7) + 31$ $4x= 3(2x+7)+31$

$4 x = 6 x + 21 + 31$ $4x= 6x+21+31$

$4 x = 6 x + 52$ $4x= 6x+52$

$2 x = - 52$ $2x=-52$

$x = - 26$ $x= -26$

put in equation (2)

$y = 2 (- 26) + 7$ $y=2(-26)+7$

$y = - 52 + 7$ $y=-52+7$

$y = - 45$ $y=-45$

How do you solve the system 4x=3y+314x=3y+314x=3y+31 and y=2x+7y=2x+7y=2x+7 by substitution?