Sow barley

Farmers wanted to sow barley within 13 days. Due to the excellent weather, they exceeded the daily plan of sowing by 2 ha and, therefore, finished sowing grain in 12 days. How many hectares of land did they sow with barley?

Correct answer:

x =  312 ha

Step-by-step explanation:

$$\begin{gathered} x=13\cdot d \\ x=12\cdot (d+2) \\ 13d-x=0 \\ 12d-x=-24 \\ Row2-\frac{12}{13}\cdot Row1\to Row2 \\ 13d-x=0 \\ -0.08x=-24 \\ x=\frac{-24}{-0.07692308}=312 \\ d=\frac{0+x}{13}=\frac{0+312}{13}=24 \\ d=24 \\ x=312=312\text{ha} \end{gathered}$$

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