3,4*(9х+0,8)-15,17=24,27
3,4*(9х+0,8)=24,27+15,17
<em>3,4*(9х+0,8)=39,44</em>
<em>9х+0,8=39,44:3,4</em>
<em>9х+0,8=11,6</em>
<em>9х=11,6-0,8</em>
<em>9х=10,8</em>
<em>х=10,8:9</em>
<em>х=1,2</em>
3 <span>3/5</span>·<span>1/3</span>=<span>3 · 5 + 3/5</span>·<span>1/3</span>=<span>18/5</span>·<span>1/3</span>=<span>18 · 1/5 · 3</span>=<span>18/15</span>=<span>15 · 1 + 3/15</span>=1 <span>3/15</span>=1 <span>1/<span>5
</span></span>1 <span>1/5</span>+3 <span>11/27</span>=<span>1 · 5 + 1/5</span>+<span>3 · 27 + 11/27</span>=<span>65</span>+<span>92/27</span>=27 · 6/27 · 5+<span>5 · 92/5 · 27</span>=162/135+<span>460/135</span>=162 + 460/135=<span>622/135</span>=135 · 4 + 82/135=4 <span>82/<span>135
</span></span>4 <span>82/135</span>-2 <span>17/18</span>=<span>4 · 135 + 82/135</span>-<span>2 · 18 + 17/18</span>=<span>622/135</span>-<span>53/18</span>=<span>2 · 622/2 · 135</span>-<span>15 · 53/15 · 18</span>=<span>1244/270</span>-<span>795270</span>=<span>1244 - 795/270</span>=<span>449/270</span>=<span>270 · 1 + 179/270</span>=1 <span>179/<span>270
</span></span><span>1 <span>179/270</span>:1 <span>23/27</span>=<span>1 · 270 + 179/270</span>:<span>1 · 27 + 23/27</span>=<span>449/270</span>:<span>50/27</span>=<span>449/270</span>·<span>27/50</span>=<span>449 · 27/270 · 50</span>=<span>12123/13500</span>=<span>449/500</span></span>
7/88*(8/21+8/7)=7/88*8/21+7/88*8/7=1/33+1/11=1/33+3/33=4/33
72-36=36 учебников .
36:4=9 ученикам достались учебники