Lời giải:

\(A=\frac{10^7-5}{10^7-8}=\frac{10^7-8+3}{10^7-8}=1+\frac{3}{10^7-8}\)

\(B=\frac{10^8+6}{10^8-7}=1+\frac{13}{10^8-7}\)

Ta thấy: \(\frac{3}{10^7-8}=\frac{30}{10^8-80}> \frac{30}{10^8-7}> \frac{13}{10^8-7}\)

\(\Rightarrow 1+\frac{3}{10^7-8}> 1+\frac{13}{10^8-7}\Rightarrow A>B\)

a)   Ta có: 

+) \(\frac{10^8}{10^7}\)-1=  10^8-7-1=10-1=9 ₍₁₎

+) \(\frac{10^7}{10^6}\)-1=  10^7-6-1=10-1=9 ₍₂₎

Từ (1) và (2) => \(\frac{10^8}{10^7}\)-1=\(\frac{10^7}{10^6}\)-1

Vậy..

\(\left(2^5\right)^8\times4^{10}=2^{40}\times\left(2^2\right)^{10}=2^{40}\times2^{20}=2^{60}\)

\(2^0\times4^{10}\times8^{12}\times16=1\times\left(2^2\right)^{10}\times\left(2^3\right)^{12}\times2^4=2^{20}\times2^{36}\times2^4=2^{60}\)

\(\Rightarrow A=B\)

A=(2⁵)⁸*4¹⁰

=2⁴⁰*(2²)¹⁰

=2⁴⁰*2²⁰

=2⁶⁰

B=2⁰*4¹⁰*8¹²*16

=1*(2²)¹⁰*(2³)¹²*2⁴

=2²⁰*2³⁶*2⁴

=2⁶⁰

Vì 2⁶⁰=2⁶⁰ =>A=B

\(A=\frac{10^8+2}{10^8-1}=\frac{10^8-1+3}{10^8-1}=\frac{10^8-1}{10^8-1}+\frac{3}{10^8-1}=1+\frac{3}{10^8-1}\)

\(B=\frac{10^8}{10^8-3}=\frac{10^8-3+3}{10^8-3}=\frac{10^8-3}{10^8-3}+\frac{3}{10^8-3}=1+\frac{3}{10^8-3}\)

Vì 10⁸-1 > 10⁸-3

=>\(\frac{3}{10^8-1}< \frac{3}{10^8-3}\)

=>\(1+\frac{3}{10^8-1}< 1+\frac{3}{10^8-3}\Rightarrow A< B\)

Ta có: A = 10⁸ + 2/ 10⁸ - 1 = 3/10⁸ - 1                           

              B = 10⁸ / 10⁸ - 3 = 3 / 10⁸ -3             

Vì 3 / 10⁸ - 1 < 3 / 10⁸ -3 nên           

Nên A< B

So sánh A và B:A=10^7+5/10^7-8            B=10^8+6/10^8-7

A=10^8+2/10^8-1=10^8-1+3/10^8-1 
=10^8-1/10^8-1+3/10^8-1=1+3/10^8-1=1/3/... 
B=10^8/10^8-3=10^8-3+3/10^8-3 
=10^8-3/10^8-3+3/10^8-3=1+3/10^8-3=1/3/... 
tu (1) va (2) =>1/3/10^8-1<1/3/10^8-3(vi phân so nao 
co mau be hon thi phân so do lon hon nen 10^8-1>10^8-3) 
Hay A<B 

k mk nha