98200 - 5689 x 4 = 98200 - 22756 = 75444

80.000 + (5980 + 4700) = 80.000+75444=90680

10208 x 3 + 47654 = 30624 + 47654 = 78278

3986 + 4695 x 7 = 8681 x 7 = 60767

98200-5689\(\times\)4=98200-22756=75444

80000+(5980-4700)=80000+12801=92801

10208\(\times\)3+47654=30624+47654=78278

3986+4695\(\times\)7=3986+32865=36851

75444    90680                  78278                   60767

\(\dfrac{1}{4}< \dfrac{a}{b}< \dfrac{2}{5}\)

=> a/b có thể bằng một trong những giá trị sau: 1/3 , 3/11, 4/11,...

Bài 2:

1.

$=(\frac{1}{7}+\frac{2}{7}+\frac{4}{7})+(\frac{3}{11}+\frac{8}{11})+2010$

$=\frac{7}{7}+\frac{11}{11}+2010=1+1+2010=2012$
2.

$=(\frac{2}{3}-\frac{2}{3})+(\frac{-3}{4}+\frac{3}{4})+(\frac{4}{5}-\frac{4}{5})+(\frac{-5}{6}+\frac{5}{6})+(\frac{6}{7}-\frac{6}{7})+(\frac{-7}{8}+\frac{7}{8})+\frac{1}{2012}$

$=0+0+0+0+0+0+\frac{1}{2012}=\frac{1}{2012}$

3.

$=\frac{1}{5-4}{4.5}+\frac{6-5}{5.6}+\frac{7-6}{6.7}+...+\frac{1}{20-19}{19.20}$

$=\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}+\frac{1}{6}-\frac{1}{7}+..+\frac{1}{19}-\frac{1}{20}$

$=\frac{1}{4}-\frac{1}{20}=\frac{1}{5}$

4.

\(=182\left[\frac{1+\frac{1}{5}-\frac{2}{7}+\frac{5}{13}}{2(1+\frac{1}{5}-\frac{2}{7}+\frac{5}{13})}: \frac{4(1-\frac{1}{33}-\frac{1}{57}+\frac{1}{7000})}{1-\frac{1}{33}-\frac{1}{57}+\frac{1}{7000}}\right]:\frac{10101\times 91}{10101\times 80}\)

$=182(\frac{1}{2}:4):\frac{91}{80}=182\times \frac{1}{8}\times \frac{80}{91}$

$=\frac{91\times 2\times 80}{8\times 91}=\frac{160}{8}=20$

MĐDS = Số dân : Diện tích 

            = triệu người / km²

Question 8

2 She has yellow hair and black eyes

3 My father likes growing many flowers in the garden

4 Many people are going o the pagoda in order to have a happy year for their family this weekend

Question 9

1 Her family has 6 people 

2 My sister really likes playing football on the weekend

3 They never make a cake on the weekend 

4 I would like you to go to the pagoda with me

1B

2B

3B

4A

5A

1B

2C

3A

4B

Đang thi tự làm

a: \(=400\cdot35=14000\)

c nhé

a: \(=400\cdot35=14000\)

b: \(=17\cdot85-120=1700-120=1580\)