[tex]B=5^{2n+3}+3^{n+3}.2^{n}-\left(5.25^{n+1}+27.6^n\right)[/tex] [tex]B=5^{2n}.5^3+3^n.3^3.2^n-5.25^n.25^1-27.6^n[/tex] [tex]B=125.5^{2n}+27.\left(3.2\right)^n-125.\left(5^2\right)^n-27.6^n[/tex] [tex]B=\cancel{125.5^{2n}}+\cancel{27.6^n}-\cancel{125.5^{2n}}-\cancel{27.6^n}[/tex] [tex]B=0[/tex] за всяко [tex]n\in N[/tex].