Explicație pas cu pas:
1)
[tex]A_{9}A_{10} = 1 + 1×8 = 9 \: cm[/tex]
[tex]A_{1}A_{10} = 1 + 2 + ... + 9 = \frac{9 \times 10}{2} = 45 \: cm[/tex]
[tex]A_{5}A_{8} = A_{5}A_{6} + A_{6}A_{7} + A_{7}A_{8} = 5 + 6 + 7 = 18 \: cm[/tex]
2)
[tex]A_{1}A_{2} = 2^{1}[/tex]
[tex]A_{2}A_{3} =2×A_{1}A_{2}= 2^{2}[/tex]
[tex]A_{3}A_{4} = 2×A_{2}A_{3}=2^{3};...[/tex]
[tex]A_{5}A_{6} = 2^{5} = 32 \: cm[/tex]
[tex]A_{8}A_{9} = 2^{8} = 256 \: cm[/tex]
[tex]A_{1}A_{4} = 2^{1}+2^{2}+2^{3} =2+4+8=14\: cm[/tex]
[tex]A_{2}A_{6} = 2^{2}+2^{3}+2^{4}+2^{5} =4+8+16+32=60\: cm[/tex]
[tex]A_{1}A_{10} = 2^{1}+2^{2}+2^{3}+...+2^{9} =2+4+8+...+512= 2×\frac{2^{9}-1}{2-1}=1022\: cm[/tex]
