21м7дм6см=2100см+70см+6см=2176см
95м4см=9500см+4см=9504см
2176см+9504см=11680см=116,8м
4т8кг=4000кг+8кг=4008кг
4008кг+995кг=4103
1) (х+0.75)+(х+0.8)=5.4
2х+1,55=5.4
2х=5.4-1.55
2х=3.85
х=3.85/2
х=1.925
2) 1.925+0.8=2.725
3) 1.925+0.75=2.720
<u>Проверка:</u> 2.720+2.725 ~ 5.4
1) M(X) = (5+4+3+2+6+3+4+8+10)/9 = 45/9 = 5
2) D(X) = (0² + 1² + 2² +3² +1² +2² +1² +3² + 5²)/89 = (1+4+9+1+4+1+9+25)/9 = 54/9 = 6
<em>1 способ</em>
<em>(х+15)-8=17</em>
<em>х+15=17+8</em>
<em>х+15=25</em>
<em>х=25-15</em>
<em>х=10</em>
<span><em>(10+15)-8=17</em>
<em>2 способ</em>
</span><em>(х+15)-8=17</em>
<span><em>х+15-8=17</em>
</span><span><em>х= 17-15+8</em>
</span><span><em>х=10</em>
</span><span><em>(10+15)-8=17</em></span>