Question

1.Tìm n,biết:

a)2x16>2ⁿ>4

b)9x27<3ⁿ<243

2.so sánh 2²²⁵và3¹⁵⁰

Answer 1

a)

\(2.16\ge2^n>4\)

\(\Rightarrow32\ge2^n>2^2\)

\(\Rightarrow2^5\ge2^n>2^2\)

\(\Rightarrow n\in\left\{3;4;5\right\}\)

Answer 2

b)

\(9.27\le3^n\le243\)

\(\Rightarrow3^2.3^3\le3^n\le3^5\)

\(\Rightarrow3^5\le3^n\le3^5\)

\(\Rightarrow n=5\)

Answer 3

còn câu 2

Answer 4

So sánh

\(2^{225}=2^{3.75}=8^{75}\)

\(3^{150}=3^{2.75}=9^{75}\)

Vì \(8< 9\Rightarrow8^{75}< 9^{75}\) hay \(2^{225}< 3^{150}\)

Answer 5

thanks