Question

So sánh A và B :A=19³⁰+5/19³¹+5 

                            B=19³¹+5/19³²+5

 Nhanh sẽ tk!!

Answer 1

19A= \(\frac{19^{31}+95}{19^{31}+5}\)  = \(\frac{19^{31}+95}{19^{31}}\)+\(\frac{19^{31}+95}{5}\)=95+ \(\frac{19^{31}+95}{5}\)

 19B=\(\frac{19^{32}+95}{19^{32}+5}\)=\(\frac{19^{32}+95}{19^{32}}\)+\(\frac{19^{32}+95}{5}\)=95+\(\frac{19^{32}+95}{5}\)

vì \(\frac{19^{31}+95}{5}\)<\(\frac{19^{32}+95}{5}\)=> 19A<19B => A<B

Answer 2

Ta có: 

\(A=\frac{19^{30}+5}{19^{31}+5}\Rightarrow19A=\frac{19\left(19^{30}+5\right)}{19^{31}+5}=\frac{19^{31}+95}{19^{31}+5}=\frac{19^{31}+5+90}{19^{31}+5}=1+\frac{90}{19^{31}+5}\)

\(B=\frac{19^{31}+5}{19^{32}+5}\Rightarrow19B=\frac{19\left(19^{31}+5\right)}{19^{32}+5}=\frac{19^{32}+95}{19^{32}+5}=\frac{19^{32}+5+90}{19^{32}+5}=1+\frac{90}{19^{32}+5}\)

Vì \(\frac{90}{19^{31}+5}>\frac{90}{19^{32}+5}\Rightarrow1+\frac{90}{19^{31}+5}>1+\frac{90}{19^{32}+5}\Rightarrow19A>19B\Rightarrow A>B\)

Answer 3

B>A vì 19^30>19^31 ; 5/19^31 < 5/19^32

Answer 4

Cảm ơn mấy bn nhìu nhìu