А)11²=121 б) 81²=6561
в) 45²=2025 г) 27²=729
д) 63²=3969 е) 55²=3025;
<span>а) 144=12²; б) 6724=82²
в) 3136=56²; г) 9801=99²
д) 5776=76²; е) 841=29²;
</span>
1!1)300000:100:1000=3км в1см 2)17•3=51км ответ 51км. 2!1)245/3.5=70км 2)70•100•1000=1:7000000.
1)
<span>(а-2)^2-а(3а-4)=
=a^2-4a+4-3a^2+4a=
=-2a^2+4
При a=-</span><span>√3
-2*(-</span><span>√3)^2+4=
=-2*3+4=
=-2
2)
</span><span>√1,6*2,7*15*20=
=</span><span>√1296=
=36</span>
Парабола ветви вверх так как а>0
вершина в точке
2х-4=0
х=4/2=2
у=2²-4*2-5=4-8-5=-6
пересечение с осью х (у=0)
х²-4х-5=0
<span><span>D=<span><span>b2</span>−<span><span>4a</span>c</span></span></span>=</span><span><span><span><span><span>(<span>−4</span>)</span>2</span>−<span><span>4·1</span>·<span>(<span>−5</span>)</span></span></span>=<span>16+20</span></span>=36</span>
<span>(<span>D>0</span>)</span>, следовательно это квадратное уравнение имеет 2 различных вещественных корня:
Вычислим корни:
<span><span>x<span>(<span>1,2</span>)</span></span>=<span><span><span>−b</span>±√D</span><span>/2a
</span></span></span><span><span><span><span>x1=<span><span><span>−b</span>+√D/</span><span>2a</span></span></span>=<span><span><span>−<span>(<span>−4</span>)</span></span>+6/</span><span>2·1</span></span></span>=<span>10/2</span></span>=5
</span><span><span><span><span>x2=<span><span><span>−b</span>−√D</span><span>/2a</span></span></span>=<span><span><span>−<span>(<span>−4</span>)</span></span>−6</span><span>/2·1</span></span></span>=<span><span>−2/</span>2</span></span>=<span>−1</span></span>
<span><span>x1</span>=5</span>
<span><span>x2</span>=<span>−<span>1
таблица точек
</span></span></span>х у
<span><span>-4 27</span><span>
-3 16</span><span>
-2 7</span><span>
-1 0
</span><span>0 -5
</span><span>1 -8</span><span>
2 -9</span><span>
3 -8</span><span>
4 -5</span><span>
5 0</span><span>
6 7
</span><span>7 16</span><span>
8 27</span></span>
1)3+3=6
Ответ:Сумма равняется 6
2)7+2=9
Ответ:Число 9