How do you solve $3x+7y=10$ and $x=18-6y$ using substitution?

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Answer 1 · 2016-03-29T23:26:33

$x=-6$
$y=4$

Solution by substitution
$3x+7y=10" "$ first equation
$x=18-6y" "$ second equation

Use the second equation into the first equation

$3x+7y=10" "$ first equation

Now use the second in place of x

$3(18-6y)+7y=10" "$ first equation

$54-18y+7y=10$

$-18y+7y=10-54$

$-11y=-44$

$y=(-44)/(-11)$

$y=4$

Use now the second equation $x=18-6y" "$ second equation and $y=4$ to solve for $x$

$x=18-6y" "$ second equation

$x=18-6(4)" "$

$x=18-24$

$x=-6$

God bless....I hope the explanation is useful.

How do you solve 3x+7y=103x+7y=10 and x=18-6yx=18-6y using substitution?