[填空题]
A farmer is going to fence two equal adjacent par 4eg fynkvh6)nvf5e8*cels of land. These parc 9w0s+lgyezryp ,y p29els share one side (which also requires fencing) as shown in the following diagram. y peylzr+ wg9y02s9p ,The farmer has only
80 metres of fence.
1. Write down the equation for the total length of the fence, 80 $\mathrm{~m}$ , in terms of x and y . y =
2. Write down the total area of both parcels of land in terms of x .
3. Find the maximum area, in $\mathrm{m}^{2}$ , of one parcel of land. ≈
