Question

Rút gọn: 

C = 7(9² + 1)(9⁴ + 1)(9⁸ + 1)(9¹⁶ + 1)

Answer 1

\(C=7\left(9^2+1\right)\left(9^4+1\right)\left(9^8+1\right)\left(9^{16}+1\right)\)

\(=7\cdot\dfrac{\left(9^2-1\right)\left(9^2+1\right)\left(9^4+1\right)\left(9^8+1\right)\left(9^{16}+1\right)}{80}\)

\(=\dfrac{7\cdot9^{32}+7}{80}\)