Question

[Nguyễn Thị Bảo An]

Rút gọn các biểu thức:

a, 10ⁿ⁺¹

b, 2ⁿ⁺³ + 2ⁿ⁺¹ - 2ⁿ⁺¹ + 2ⁿ.

c, 90.10^k - 10^k+2 + 10^k+1.

d, 2,5.5^n-3 - 10.5ⁿ - 6.5^n-1.

Answer 1

[Nguyễn Lê Phước Thịnh]

a: \(10^{n+1}=10^n\cdot10\)

b: \(2^{n+3}+2^{n+1}-2^{n+1}+2^n\)

\(=2^n\cdot8+2^n=9\cdot2^n\)

c: \(90\cdot10^k-10^{k+2}+10^{k+1}\)

\(=90\cdot10^k+10^k\cdot10-10^k\cdot100=0\)