<span> 3x-y=14</span>
<span><span>-3x+5y=10</span></span>
<span><span>4y=24</span></span>
<span><span>y=24/4</span></span>
<em><u><span><span>y=6</span></span></u></em>
<em><u /><span><span /></span></em><span><span /></span><span><span>3x-y=14</span></span>
<span><span>3x-6=14</span></span>
<span><span>3x=14+6</span></span>
<span><span>3x=20</span></span>
<em><u><span><span>x=20/3</span></span></u></em>
<em><u /><span><span /></span></em><span><span /></span><span><span><span> x+4y=9-умножим обе части уравнения на(-3)</span></span></span>
<span><span><span>3x+7y=2</span></span></span>
<span><span><span>-3х-12у=-27</span></span></span>
<span><span><span>3x+7y=2</span></span></span>
<span><span><span>-5у=-25</span></span></span>
<span><span><span>у=(-25)/(-5)</span></span></span>
<em><u><span><span><span>у=5</span></span></span></u></em>
<em><u /><span><span><span /></span></span></em><span><span><span /></span></span><span><span><span><em /> x+4y=9</span></span></span>
<span><span><span>х+4*5=9</span></span></span>
<span><span><span>х+20=9</span></span></span>
<span><span><span>х=9-20</span></span></span>
<em><u><span><span><span>х=-11</span></span></span></u></em>
<em><u /><span><span><span /></span></span></em><span><span><span /></span></span><span><span><span>пусть х-первое число</span></span></span>
<span><span><span> у-второе число</span></span></span>
<span><span><span>х-у=12</span></span></span>
<span><span><span>2х+у=27</span></span></span>
<u><span><span><span>х=12+у</span></span></span></u>
<span><span><span>2(12+у)+у=27</span></span></span>
<span><span><span>24+2у+у=27</span></span></span>
<span><span><span>3у=27-24=3</span></span></span>
<span><span><span>у=3/3</span></span></span>
<em><u><span><span><span>у=1</span></span></span></u></em>
<em><u /><span><span><span /></span></span></em><span><span><span /></span></span><span><span><span><u>х=12+у</u></span></span></span>
<span><span><span>х=12+1</span></span></span>
<em><u><span><span><span>х=13</span></span></span></u></em>
