\(\frac{16}{15.31}+\frac{14}{31.45}+\frac{7}{45.52}+\frac{13}{52.65}+\frac{1}{13.70}\)

\(=\frac{16}{15.31}+\frac{14}{31.45}+\frac{7}{45.52}+\frac{13}{52.65}+\frac{5}{65.70}\)

\(=\frac{1}{15}-\frac{1}{31}+\frac{1}{31}-\frac{1}{45}+\frac{1}{45}-\frac{1}{52}+\frac{1}{52}-\frac{1}{65}+\frac{1}{65}-\frac{1}{70}=\frac{1}{15}-\frac{1}{70}=\frac{11}{210}\)

. Tham khảo nha !!! 

\(\frac{16}{15.31}+\frac{14}{31.45}+\frac{7}{45.52}+\frac{7}{52.65}+\frac{1}{13.70}\)

\(=\frac{16}{15.31}+\frac{14}{31.45}+\frac{7}{45.52}+\frac{7}{52.65}+\frac{5}{65.70}\)

\(=\frac{1}{15}-\frac{1}{31}+\frac{1}{31}-\frac{1}{45}+\frac{1}{45}-\frac{1}{52}+\frac{1}{52}-\frac{1}{65}+\frac{1}{65}-\frac{1}{70}\)

\(=\frac{1}{15}-\frac{1}{70}\)

\(=\frac{70}{1050}-\frac{15}{1050}\)

\(=\frac{55}{1050}\)

\(=\frac{11}{210}\)

Chúc bạn học tốt !!! 

= 1/15 - 1/31 + 1/31 - 1/45 + 1/45 - 1/52 + 1/52 - 1/65 + 1/13.70

= 1/15 - 1/65 + 1/13.70

= 2/39 + 1/910

= 11/210

Tk mk nha

=(1/15-1/31+1/31-1/45+1/45-1/52+1/52-1/65)+1/910

​=(1/15-1/65)+1/910

​=2/39+1/910=140/2730+3/2730=11/210

​Tk mình nha bn !

​

37/663

giúp mk đi, mai mk nộp rùi đó

Lời giải:

$A=\frac{15-5}{5.15}+\frac{31-15}{15.31}+\frac{45-31}{31.45}+\frac{52-45}{45.52}+\frac{65-52}{52.65}+\frac{1}{13.70}+\frac{1}{70.15}$

$=\frac{1}{5}-\frac{1}{15}+\frac{1}{15}-\frac{1}{31}+\frac{1}{31}-\frac{1}{45}+\frac{1}{45}-\frac{1}{52}+\frac{1}{52}-\frac{1}{65}+\frac{1}{70}(\frac{1}{13}+\frac{1}{15})$

$=\frac{1}{5}-\frac{1}{65}+\frac{1}{70}.\frac{28}{195}$

$=\frac{12}{65}+\frac{2}{95}$

$=\frac{254}{1325}$

\(\dfrac{1}{4444}< 1,\dfrac{3}{7}< 1,\dfrac{9}{5}>1,\dfrac{7}{3}>1,\dfrac{14}{15}< 1,\dfrac{16}{16}=1,\dfrac{14}{11}>1\)

1/4 < 1

3/7 < 1

9/5 > 1

7/3 > 1

14/15 < 1

16/16 = 1

14/11 >1

\(\frac{1}{4}< 1\) ; \(\frac{3}{7}< 1\) ; \(\frac{9}{5}>1\)

\(\frac{7}{3}>1\) ; \(\frac{14}{15}< 1\) ; \(\frac{16}{16}=1\) ; \(\frac{14}{11}>1\)

1/4  < 1;     3/7 < 1;     9/5 > 1;        14/15 < 1;        16/16 = 1;       14/11 > 1.

TL

1/4 < 1;

3/7 < 1;

9/5 > 1;

7/3 > 1;

14/15 < 1;

16/16 = 1;

14/11 > 1.

HT

a,  4 . 24 . 5 2 - 3 3 . 18 + 3 3 . 12

= 100.24–27.30

= 2400 – 810

= 1590

b,  2 3 . 7 . 5 3 - 5 2 . 65 + 5 2 . 35

= 7.1000 – 25.100

= 7000 – 2500

= 4500

c,  2 2 . 74 . 5 2 + 5 2 . 26 . 4 - 7000

= 100.74 + 100.26 – 70.100

= 100.(74+26–70)

= 100.30

= 3000

d,  55 . 2 2 . 5 + 4 . 89 . 5 2 - 3 2 . 10 3

= 25.4.11 + 4.25.89 – 90.100

= 100.11 + 100.89 – 100.90

= 100.(11+89–90)

= 100.10

= 1000

e, [(315+372).3+(372+315).7]:(26.13+74.13+74)

= [687.3+687.7]:(13.(26+74)+74)

= (687.10):(13.100+74)

= 6870:1374

= 5