Tree planting area

The forestry plant plants new trees on a rectangular area 1.8 km long and 880 m wide. In the first week, they planted 3/11 of the total area. In the second week, they had 4/9 of the total area. How many hectares are left to plant?

Final Answer:

x =  44.8 ha

Step-by-step explanation:

$$\begin{gathered} a=1.8\text{km}\to \text{m}=1.8\cdot 1000\text{m}=1800\text{m} \\ b=880\text{m} \\ S=a\cdot b=1800\cdot 880=1584000{\text{m}}^2 \\ q=1-\frac{3}{11}-\frac{4}{9}=\frac{28}{99}\doteq 0.2828 \\ {S}_2=q\cdot S=\frac{28}{99}\cdot 1584000=\frac{28\cdot 1584000}{99}=\frac{44352000}{99}=448000{\text{m}}^2 \\ x=S_2\to \text{ha}=S_2:10000\text{ha}=448000:10000\text{ha}=44.8\text{ha}=\frac{224}{5}\text{ha}=44.8\text{ha} \end{gathered}$$

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