(3)2/7 * 8,5 - 1,5 * (3)2/7 = (3)2/7 * (8,5 - 1,5) = (3)2/7 * 7 = 23/7 * 7 = 23
-7-6-5-4-3-2-1+1+2+3+4+5+6+7+8+9+10+11+12=50
<em>1) 9х2=18 </em>
<em>2)18+12=30.</em>
<em>-------------------------------</em>
<em>1)15:5=3</em>
<em>2)3+17=20</em>
1.125x5600=700000
2.875x204=178500
3.700000-178500=521500
4 <span>521500 : 500 =1043</span>