Ответ в прикрепленном файле =)
...................................................................= -1,62
1) -1/18 + 1/6= - 1/18 + 3/18=2/18=1/9
2) 0,31 - 0,69= - 0,38
3) 1/9 - 2 1/9= - 2
4) -(-0,38) - 2= 0,38-2= - 1,62
<span>500:5=100(м)-проходит в 1 минуту
1 час = 60 минут
100*60=<span>6000(м) = 6 км - пройдет за 1 час</span></span>
<span><span>−5x2+21x−18</span>2x2−3x</span>=<span>0
</span><span><span>−5x2+21x</span>−18</span>=<span>0
</span><span><span>(<span>−5x+6</span>)</span>(x−3)</span>=<span>0
</span><span><span><span>−5x</span>+6</span>=<span><span><span>0 or </span>x</span>−3</span></span>=<span>0
</span><span>x=<span><span><span>65</span><span> or </span></span>x</span></span>=<span>3</span>