1    \(A=\left(1+\frac{1}{2}\right)\times\left(1+\frac{1}{3}\right)\times\left(1+\frac{1}{4}\right)\times.........\times\left(1+\frac{1}{2016}\right)\times\left(1+\frac{1}{2017}\right)\)

\(A=\frac{3}{2}\times\frac{4}{3}\times\frac{5}{4}\times......\times\frac{2016}{2017}\times\frac{2018}{2017}\)

\(A=\frac{2018}{2}=1009\)

\(B=\frac{2}{3.5}+\frac{2}{5.7}+\frac{2}{7.9}+.......+\frac{2}{43.45}\)

\(B=\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-\frac{1}{7}+\frac{1}{7}-......+\frac{1}{43}-\frac{1}{45}\)

\(B=\frac{1}{3}-\frac{1}{45}\)

\(B=\frac{14}{45}\)

2     \(\frac{2017}{2018}\times\frac{23}{47}+\frac{24}{2018}\times\frac{2017}{47}\)

\(=\frac{2017}{2018}\times\frac{23}{47}+\frac{24}{47}\times\frac{2017}{2018}\)

\(=\frac{2017}{2018}\times\left(\frac{23}{47}+\frac{24}{47}\right)\)

\(=\frac{2017}{2018}\times1\)

=\(\frac{2017}{2018}\)

bạn nào xem giải thế có đúng ko

\(6-\left(\frac76+\frac{7}{18}\right)\)

\(=6-\left(\frac{7\times3}{6\times3}+\frac{7}{18}\right)\)

\(=6-\left(\frac{21}{18}+\frac{7}{18}\right)\)

\(=6-\left(\frac{21+7}{18}\right)\)

\(=6-\frac{28}{18}\)

\(=6-\frac{28:2}{18:2}\)

\(=6-\frac{14}{9}\)

\(=\frac{6\times9}{1\times9}-\frac{14}{9}\)

\(=\frac{36}{9}-\frac{14}{9}\)

\(=\frac{54-14}{9}\)

\(=\frac{40}{9}\)

cong hai cái số trong ngoac rồi lấy 6 đổi ra 6'1 trừ đi

\(5\times\left(6+7\right)\)

\(C1:5\times\left(6+7\right)\)

\(=5\times13\)

\(=65\)

\(C2:5\times\left(6+7\right)\)

\(=5\times6+5\times7\)

\(=30+35\)

\(=35\)

Chúc bạn học tốt !!!

5 x ( 6 + 7 ) 

= 5 x 13 

= 65

Tk cho mk nha !!

Ta có a - b = 4 

suy ra a > b

ta có các cặp ab: 40; 51;62;73;84;95

sau đó b lần lượt thay số thì sẽ ra kết quả là a=8 ; b=4 nhé

#chanh

bn oi

ket qua cua bai nay la ab bang 84 nha

k cho mk

1tuần=7ngày

7+7=14=>ab=14

14x2=28=>cd=28

abcd là 1428

bai toan nay 

(a+b) x 2=88 => a+b=44

(b+c) x 2= 148 => b+c=74

(a+c) x 2=108 => a+c=54

(c+d) x 2=208 => c+d=104

(b+d) x 2=188 => b+d=94

(a+d) x 2=148 => a+d= 74

=> a+b+b+c+a+c+c+d+b+d+a+d = 44+74+54+104+94+74

=> 3 x a + 3 x b + 3 x c + 3 x d = 444

3 x (a+b+c+d) = 444

a+b+c+d = 444 : 3

a+b+c+d = 148

A.9 KG-Đúng

Đương nhiên B là SAI rồi!!! 

nhanhleen mình cần gấp huhu!!

M = (345 x (6789 + 3456 - 245)/690) x 99/100 x 98/99 x...x 2/3 x 1/2
M = ((345 x 10000)/690) x 99/2 (rút gọn)
M = (10000/2) x 99/2
M = 5000 x 99/2
M = 247500
Ok nha

a: \(\left(\frac{11}{4}-\frac78\right):\frac{11}{2}\)

\(=\left(\frac{22}{8}-\frac78\right)\times\frac{2}{11}\)

\(=\frac{15}{8}\times\frac{2}{11}=\frac{15}{4\times11}=\frac{15}{44}\)

b: Sửa đề: \(\frac{29}{44}:\frac{15}{44}\times\frac{15}{88}:\frac{165}{16}\)

\(=\frac{29}{44}\times\frac{44}{15}\times\frac{15}{88}\times\frac{16}{165}\)

\(=\frac{29}{88}\times\frac{16}{165}=29\times\frac{2}{11\times165}=\frac{58}{1815}\)