Garden

The garden is rectangular and has lengths of 25 and 40 meters. It has been expanded so that each size increased by one-fifth. How many square meters increased its acreage?

Correct answer:

x =  440 m²

Step-by-step explanation:

$$\begin{gathered} a=25\text{m} \\ b=40\text{m} \\ {S}_1=a\cdot b=25\cdot 40=1000{\text{m}}^2 \\ q=1+\frac{20}{100}=\frac{1\cdot 100}{100}+\frac{20}{100}=\frac{100}{100}+\frac{20}{100}=\frac{100+20}{100}=\frac{120}{100}=\frac{6}{5}=1.2 \\ {a}_2=a\cdot q=25\cdot \frac{6}{5}=\frac{25\cdot 6}{5}=\frac{150}{5}=30\text{m} \\ {b}_2=b\cdot q=40\cdot \frac{6}{5}=\frac{40\cdot 6}{5}=\frac{240}{5}=48\text{m} \\ {S}_2=a_2\cdot b_2=30\cdot 48=1440{\text{m}}^2 \\ x=S_2-S_1=1440-1000=440{\text{m}}^2 \end{gathered}$$

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