ket qua =1/2

mk đang cần gấp người giải ai thấy bài này giải giúp mk nha 

a) x-5/7=3/5x1/2
    x-5/7=3/10
    x.     =3/10+5/7
    x.     =71/70
b) Xx2/3=5/8x3/4
    Xx2/3=15/32
    X       =15/32:2/3
    X       =45/64

a) x - 5/7 = 3/5 × 1/2

x - 5/7 = 3/10

x = 3/10 + 5/7

x = 71/70

b) x × 2/3 = 5/8 × 3/4

x × 2/3 = 15/32

x = 15/32 : 2/3

x = 45/64

1. 3/2  ..............the third of February.................

2. 20/11  ......the twentieth of November..................

3. 30/4   ..........the thirtieth of April...............

4. 22/12 ..the twenty second of December..............

5. 2/9 .........the second of September................

6. 26/3  ........the twenty sixth of March...............

7. 19/8  ............the nineteenth of August.................

8. 10/10   .........the tenth of October...................

9. 7/5   ...........the seventh of May..................

10. 27/7  .........the twenty seventh of July................

Em hãy viết theo cách đọc những ngày tháng sau.

Ví dụ: 1/1: the first of January

1. 3/2  : The third of February .

2. 20/11  : The twentith - two of November .

3. 30/4  : The thirtith of April .

4. 22/12 : The twentith - two of December .

5. 2/9 : The second of September .

6. 26/3  : The twentith of March

7. 19/8  : The nineteenth of August

8. 10/10 : The tenth of October .

9. 7/5 : The seventh of May

10. 27/7 : The twentith - seven of July.

\(4\frac{5}{7}:1=\frac{33}{7}:1==\frac{33}{7}\)

\(\frac{5}{6}+2=\frac{5}{6}+\frac{12}{6}=\frac{17}{6}\)

\(\frac{7}{15}x\frac{21}{74}=\frac{7}{3x5}x\frac{3x7}{74}=\frac{7x7}{5x74}=\frac{49}{370}\)

5=1 chớ!^^

1=5

2=6

3=7

4=8

5=9

ta có : (x+5) < 0

<=> x<-5

vậy  x ={ -6 ; -7 ; ..............}

toán chứng minh chỉ có giả sử các trường hợp chứ làm j có chuyện ví dụ!

\(\frac{4}{9}:8-\left(\frac{1}{4}+\frac{9}{20}\right):1\frac{4}{5}\)

\(=\frac{1}{18}-\frac{7}{10}\cdot\frac{5}{9}=\frac{1}{18}-\frac{7}{18}=-\frac{1}{3}\)

\(\frac{4}{9}:8-\left(\frac{1}{4}+\frac{9}{20}\right):1\frac{4}{5}\)

\(=\frac{1}{18}-\frac{5+9}{20}\times\frac{5}{9}\)

\(=\frac{1}{18}-\frac{14\times5}{20\times9}\)

\(\frac{1}{18}-\frac{14}{36}=\frac{2-14}{36}=\frac{-12}{36}=\frac{-1}{3}\)