a) 123 + (– 3)  < 123

          b) (– 97) + 7 > (– 97)

A = \(\dfrac{3^{123}+1}{3^{125}+1}\)  Vì 3¹²³ + 1 < 2¹²⁵ + 1 Nên A = \(\dfrac{3^{123}+1}{3^{125}+1}\)< \(\dfrac{3^{123}+1+2}{3^{125}+1+2}\)

A < \(\dfrac{3^{123}+3}{3^{125}+3}\) = \(\dfrac{3.\left(3^{122}+1\right)}{3.\left(3^{124}+1\right)}\) = \(\dfrac{3^{122}+1}{3^{124}+1}\) = B

Vậy A < B 

Ta có: 5 = ∛53 = ∛125

Vì ∛125 > ∛123 nên 5 > ∛123

\(\dfrac{123}{7}=17,\left(571428\right)=17,5714285714...\)

Vì \(17,5714285714...< 17,75\)

nên \(\dfrac{123}{7}< 17,75\)

Ta có: \(\dfrac{123}{7}=17,\left(571428\right)\approx17,57\)

Xét thấy \(17,57< 17,75\Rightarrow\dfrac{123}{7}< 17,75\)

ai trả lời đúng mik tick cho

456/461 > 123/128

456/461 > 123/128

k nhé

ta có :

\(1-\frac{456}{461}=\frac{5}{461}\)

\(1-\frac{123}{128}=\frac{5}{128}\)

Vì \(\frac{5}{461}< \frac{5}{128}\)nên \(\frac{456}{461}< \frac{123}{128}\)

bài này mk sử dụng so sánh phần bù nha bạn ! ok !