Bai 3. 

A) cac tia Ax, AM, AC, AB, Az, Ay

B) AM, AC

Bai 3. 

A) cac tia Ax, AM, AC, AB, Az, Ay

B) AM, AC

Bai 2                                                            Giai

Sau khi giam gia , gia cua 1 quyen tap la:

7000-( 7000:10)=6300(dong)

So tien mua 15 quyen tap la:

6300X15= 94500( dong)

                         Vay : Ban an du tien mua 15quyen tap va con du 5500dong

A)= 1/2+1/3

= 5/6

B) =2/5+2/3

=16/15

C) =7/11x( 3/4+1/4)+4/11

=7/11x1+4/11

= 1

D) =( 3/4+1/2+1/4)x8/3

= 3/2x8/3

= 4

A) Vi diem M la trung diem cua doan thang AB

Suy ra $AM = MB =/dfrac{AB}2=/dfrac 42=2(cm)

B) Truong hop 1:

xMy=60

Truong hop 2:

xMy= 160

so hoc sinh gioi cua lop 6A la : 

7/20. 40 = 14(hoc sinh)

so hoc sinh trung binh cua lop 6A la:

1/8 . 40 = 5 (hoc sinh)

so hoc sinh kha cua lop 6A la:

14 + 5 = 19 (hoc sinh)

so hoc sinh yeu cua lop 6A la :

40 -( 14 + 5 + 19) = 2 ( hoc sinh)

         Vay 2 hoc sinh

A) 1/2 . 4/3 - 20/3 . 4/5

= 2/3 - 16/3

= -14/3

B) 3/7+ -6/19 +4/7 + -13/19

=( 3/7+4/7) + ( -6/19 +-13/19)

=7/7+ 19/19

=1+(-1)

=0

C) 3/5. 8/9 - 7/9 . 3/5 + 3/5 . 29/9

=3/5 . ( 8/9 - 7/9+ 29/9)

=3/5 . 27/9

=3/5.3

=9/5

A) 1/2 . 4/3 - 20/3 . 4/5

= 2/3 - 16/3

= -14/3

B) 3/7+ -6/19 +4/7 + -13/19

=( 3/7+4/7) + ( -6/19 +-13/19)

=7/7+ 19/19

=1+(-1)

=0

C) 3/5. 8/9 - 7/9 . 3/5 + 3/5 . 29/9

=3/5 . ( 8/9 - 7/9+ 29/9)

=3/5 . 27/9

=3/5.3

=9/5

A) 1/2 . 4/3 - 20/3 . 4/5

= 2/3 - 16/3

= -14/3

B) 3/7+ -6/19 +4/7 + -13/19

=( 3/7+4/7) + ( -6/19 +-13/19)

=7/7+ 19/19

=1+(-1)

=0

C) 3/5. 8/9 - 7/9 . 3/5 + 3/5 . 29/9

=3/5 . ( 8/9 - 7/9+ 29/9)

=3/5 . 27/9

=3/5.3

=9/5

A) 1/2 . 4/3 - 20/3 . 4/5

= 2/3 - 16/3

= -14/3

B) 3/7+ -6/19 +4/7 + -13/19

=( 3/7+4/7) + ( -6/19 +-13/19)

=7/7+ 19/19

=1+(-1)

=0

C) 3/5. 8/9 - 7/9 . 3/5 + 3/5 . 29/9

=3/5 . ( 8/9 - 7/9+ 29/9)

=3/5 . 27/9

=3/5.3

=9/5