<PRE><B>Question 125638</B>
I need help!

solve each system of equations by elimination

5x - 4y = 23

7x + 8y = 5

Thanks&lt;br&gt;&lt;br&gt;

Multiply the first equation by 2, so that the y&#39;s cancel out.
{{{10x-8y=46}}}
{{{7x+8y=5}}}&lt;br&gt;&lt;br&gt;

Add the like terms:
{{{17x=51}}}&lt;br&gt;&lt;br&gt;

Divide both sides by 17:
{{{x=3}}}&lt;br&gt;&lt;br&gt;

Plug this value into one of the original equations:
{{{5(3)-4y=23}}}&lt;br&gt;&lt;br&gt;

Multiply:
{{{15-4y=23}}}&lt;br&gt;&lt;br&gt;

Subtract 15 from both sides:
{{{-4y=8}}}&lt;br&gt;&lt;br&gt;

Divide both sides by -4:
{{{y=-2}}}&lt;br&gt;&lt;br&gt;

So, x=3 and y=-2&lt;br&gt;&lt;br&gt;

-buildings

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