х---------<span>вік</span><span> </span><span>молодшого</span><span> </span><span>брат</span>
2х-------<span>вік</span><span> </span><span>середнього</span><span> </span><span>брата</span>
<span>2х*2 <span>або</span></span>
4х-------<span>вік</span><span> </span><span>старшого</span><span> </span><span>брата</span>
х+2х+4х=28
<span>7х=28</span>
<span>х=28:7</span>
<span>х=4 <span>року</span><span> </span><span>молодшому братові</span>
<span>2*4=8 років</span><span> </span><span>середньому</span><span> </span><span>братові</span></span>
<span> 2*4*2=16 або
<span>4*4=16 років</span><span> </span><span>старшому</span><span> </span><span>братові.</span></span>
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</span>
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