4/9>3/10

11/19<13/18

a) Ta có: 

\(A=-3\cdot7\cdot\left(-2\right)\cdot\left(-13\right)\)

\(A=-21\cdot26\)

\(A=-546\)

\(B=-1\cdot\left(-2\right)\cdot\left(-3\right)\cdot\left(-4\right)\cdot5\)

\(B=2\cdot12\cdot5\)

\(B=2\cdot60\)

\(B=120\)

Mà: \(120>-546\)

\(\Rightarrow B>A\)

bài 1 :

a)\(2,5.16,27.4+7,3=\left(2,5.4\right).16,27+7,3=10.16,27+7,3\)

\(=162,7+7,3=170\)

b) \(\frac{2}{3}+\frac{3}{4}-\frac{5}{6}=\left(\frac{2}{3}-\frac{5}{6}\right)+\frac{3}{4}=\frac{-1}{6}+\frac{3}{4}=\frac{7}{12}\)

c) \(17,6-5,3+16,8-7,6+15,3-6,8\)

\(=\left(17,6-7,6\right)+\left(-5,3+15,3\right)+\left(16,8-6,8\right)\)

\(=10+10+10=30\)

d)\(\frac{38}{11}+\left(13,16+\frac{6}{11}\right)=\frac{38}{11}+13,16+\frac{6}{11}\)

\(=\left(\frac{38}{11}+\frac{6}{11}\right)+13,16=4+13,16=17,16\)

\(2,45.46+8.0,75+54.2,45+0,5.8\\ =\left[2,45.46+54.2,45\right]\)

\(+\left[8.0,75+0,5.8\right]=\left[2,45.\left(46+54\right)\right]+\left[8.\left(0,75+0,5\right)\right]\)

\(=\left(2,45.100\right)+\left(8.1,25\right)=245+10=255\)

 bài 2 :

a) .....

b) \(1-\left(12,5+x-4,25\right):21,75=0\)

\(\Rightarrow1-\left(12,5+x-4,25\right)=21,75\)

\(\Rightarrow12,5+x-4,25=-20,75\\ \Rightarrow12,5+x=-16,5\)

\(\Rightarrow x=-29\)

cậu có thể tham khảo bài làm trên đây ạ, mn ai thấy đúng thì cho mk xin 1 t.i.c.k đúng ạ ,thank nhiều

mọi người ơiii ! giải giúp em với ạ :(((

1.

a) \(-\frac{15}{17}>-\frac{19}{21}\)

b)\(-\frac{13}{19}>-\frac{19}{23}\)

c)\(-\frac{23}{49}>-\frac{25}{47}\)

d)\(\frac{317}{633}>\frac{371}{743}\)

e)\(-\frac{24}{35}< -\frac{19}{30}\)

f)\(\frac{12}{17}< \frac{13}{18}\)

g) \(-\frac{17}{26}< -\frac{16}{27}\)

h) \(\frac{84}{-83}< -\frac{337}{331}\)

i) \(-\frac{1941}{1931}< -\frac{2011}{2001}\)

j) \(-\frac{1930}{1945}>-\frac{1996}{2001}\)

k) \(\frac{37}{59}< \frac{47}{59}\)

I) \(-\frac{25}{124}>-\frac{27}{100}\)

m) \(-\frac{97}{201}>-\frac{194}{309}\)

n) \(-\frac{189}{398}< -\frac{187}{394}\)

o) \(-\frac{289}{403}>-\frac{298}{401}\)

Mắm Tôm Nè UID FF 1104310266 

a) \(\dfrac{3}{4}=\dfrac{3x4}{4x4}=\dfrac{12}{16},\dfrac{6}{7}=\dfrac{6x2}{7x2}=\dfrac{12}{14}\)

Do 16 > 14 => \(\dfrac{12}{16}< \dfrac{12}{14}hay\dfrac{3}{4}< \dfrac{6}{7}\)

1216<1214hay34<67

TL :

Đây nhé

HT

@@@@@@@@@@@@@@@@@

a) 4/7 < 1 < 7/4 => 4/7 < 7/4

b) 11/12 so sánh 9/10

    Vì 1/12 < 1/10 nên 11/12 > 9/10 (so sánh phần bù)

c)12/19 so sánh 26/33

    Vì 7/19 > 7/33 nên 12/19 < 26/33 (so sánh phần bù)

d)7/13<1<13/7 => 7/13 < 13/7

a)3/13*2/2roi so sanh

a,>

b,<

c,<

c)13/25*4/4 roi so sanh voi53/100