Question

[Anime Phim]

Rút gọn biểu thức sau

a) 90.10^k-10^k+2+10^k+1

b) 2,5.5^n-3.10+5ⁿ-6.5^n-1

Answer 1

[Ngọc Minh]

a) Ta có:

90.10^k−10^k+2+10^k+1

=90.10^k−10^k.10²+10^k.10

=10^k(90−10²+10)

=10^k.0=0