A=988 x 988

B=986 x 990

suy ra A=988 x (988+2)

B=(986+2) x 990 

Â=988 x 988 +988 x 2

B=986 x 2+986 x990

Vậy suy ra tích A> B

tick nha Bảo Anh

A = \(\frac{976}{987}\) + \(\frac{987}{988}\) = \(1,987842971\)

B = \(\frac{986+987}{987+988}\)= \(\frac{1973}{1975}\) = \(0,9989873418\)

Mà \(1,987842971\)> \(0,9989873418\)

Nên: A > B

Ta có: \(\frac{986}{987}>\frac{986}{987+988}\)

\(\frac{987}{988}>\frac{987}{987+988}\)

\(\Rightarrow\frac{976}{987}+\frac{987}{988}>\frac{986+987}{987+988}\)

=> A > B

√988 = √9,88.√100 = 3,143.10 = 31,43

a) √911 = √9,11.√100 = 3,018.10 = 30,18

b) √988 = √9,88.√100 = 3,143.10 = 31,43

tất cả =1 nha

899 - 988 = -89

677 - 766 = -89

899-988

=-89

677-766

=-89

a)899-988

=--89

b)677-766

=-89

Đáp án D