= 4 (m² - 2·m·n+ n² ) + 4 m² - 4m·n =
= 4 m² - 8 m n + 4 n² + 4 m²- 4 m n =
= 8 m ² - 12 m n + 4 n ²
-2/5:0,9=-2/5:9/10=-2/5×10/9=-2×10/5×9=-2×2/1×9=-4/9=
-2/3×7/8=-2×7/3×8=1×7/3×4=-7/12
0,5-5/6=5/10-5/6=3×5-5×5/30=15-25/30=-10/30=-1/3
-7,12;-4/9;-1/3.
1)158-12=146
2)158+146=304
3)304+40=344
344{380, значит мест хватило
4500г*3*1=13500г, т.е.13кг 500г.