How do you solve $2x = 4$ and $2x – y = 5$ ?

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Answer 1 · 2015-08-21T11:31:59

${(x = 2), (y = -1) :}$

Notice that you can find the value of $x$ from the first equation by dividing both sides by $2$

$(color(red)(cancel(color(black)(2))) * x)/color(red)(cancel(color(black)(2))) = 4/2$

$x = color(green)(2)$

Now simply take this value of $x$ and plug it into the second equation. This will allow you to find the value of $y$

$2x - y = 5$

$2 * (2) - y = 5$

$4 - y = 5$

This is equivalent to

$y = 4 -5 = color(green)(-1)$

How do you solve 2x = 42x = 4 and 2x – y = 52x – y = 5?