Первое число - 100х + 10у + 7
Второе число - 700 + 10х + у
<span>(100х + 10у + 7)*3 - 17 = <span>700 + 10х + у</span></span>
<span><span><span>300х+30у+21-17= 700+10х+у</span></span></span>
<span><span><span><span>290х+29у=696 </span></span></span></span>
<span><span><span><span><span>10х+у=24 </span></span></span></span></span>
<span><span><span><span><span><span>т.е. х=2, подставим его в любое уравнение получим - у=4 ...От сюда... <span>числа 247 и 724</span></span></span></span></span></span></span>
<span><span><span><span><span><span><span>
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<span><span><span><span><span><span><span>Проверка:</span></span></span></span></span></span></span>
<span><span><span><span><span><span><span><span>247*3=741</span></span></span></span></span></span></span></span>
<span><span><span><span><span><span><span><span><span>741-17=724</span></span></span></span></span></span></span></span></span>
А)
<span>{2х-у=8 /х(-3)
</span><span>{2х-3у=-4
</span><span>{-6х+3у=-24
</span><span>{2х-3у=-4
</span>-4х=-28
х=7
14-у=8
-у=8-14
-у=--6
у=6
б)
{3x+2y=9 /х(-1)
{x+2y=3
<span>{-3х-2у=-9
</span><span>{х+2у=3
</span>-2х=-6
х=3
3+2у=3
2у=0
у=0