Explicație pas cu pas:
9. P = 4×l și A = l²
[tex]\frac{l_{1}}{l_{2}} = \frac{7}{2} \\ [/tex]
[tex]\frac{P_{1}}{P_{2}} = \frac{4 \times l_{1}}{4 \times l_{1}} = \frac{l_{1}}{l_{2}} = \frac{7}{2} \\ [/tex]
[tex]\frac{A_{1}}{A_{2}} = \frac{ {l_{1}}^{2} }{{l_{2}}^{2}} = \left(\frac{l_{1}}{l_{2}} \right)^{2} = \left(\frac{7}{2} \right)^{2} = \frac{49}{4} \\ [/tex]
10. A = L×l
[tex]\frac{L_{1}}{L_{2}} = \frac{8}{5} \\ [/tex]
[tex]\frac{l_{1}}{l_{2}} = \frac{4}{3} \\ [/tex]
[tex]\frac{A_{1}}{A_{2}} = \frac{L_{1} \times l_{1}}{L_{2} \times l_{12}} = \frac{L_{1}}{L_{2}} \times \frac{l_{1}}{l_{2}} = \frac{8}{5} \times \frac{4}{3} \\ = \frac{8 \times 4}{5 \times 3} = \frac{32}{15} [/tex]
