<span>0,7х+0,01х+0,074=0,5</span>
<span>0,71х=0,5-0,074</span>
<span>0,71х=0,426</span>
<span>х=0,426:0,71</span>
<span>х=0,6</span>
<span>проверка:</span>
<span>0,7*0,6+0,01*0,6+0,074=0,5</span>
<span>0,5=0,5</span>
<span></span>
x*45=2250
x=2250:45
x=50