II.
[tex]\bf 1.\ \ \it 28+2(2660+76:x):893=34\Big|_{-28} \Rightarrow 2(2660+76:x):893=6|_{:2} \Rightarrow \\ \\ \Rightarrow (2660+76:x):893=3|_{\cdot893} \Rightarrow 2660+76:x=2679|_{-2660} \Rightarrow \\ \\ \Rightarrow 76:x=19 \Rightarrow x=76:19 \Rightarrow x=4[/tex]
[tex]\bf2.\ \ \it =2^7:2^6+3^9\cdot3^{15}:3^{20}+(48-16):8=2+3^4+32:8=2+81+4=87[/tex]
[tex]\bf3.\ \ \it a=(3^{21}+3^{20}+3^{18}):37=3^{18}(27+9+1):37=(3^9)^2\cdot37:37=(3^9)^2[/tex]
4. Notăm:
b - suma lui Bogdan;
a - suma Anei.
[tex]\it b=5a\ \ \ \ \ (1)\\ \\ b-a=160 \Rightarrow b=160+a\ \ \ \ \ (2)\\ \\ (1),\ (2) \Rightarrow 5a=160+a\Big|_{-a} \Rightarrow 4a=160|_{:4} \Rightarrow a=40\ \ell ei\ \ \ \ \ (3)\\ \\ (1),\ (3) \Rightarrow b=5\cdot40 \Rightarrow b=200[/tex]
Bogdan are 200 de lei, iar Ana are 40 de lei.
