Nguyễn Yến Nhi
Giới thiệu về bản thân
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
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
3 - 1/1.3 + 5 -3 + 7- 5/5.7+....+101-99/99.101
= 3/1.3 - 1/1.3+ 5/3.5 - 3/3.5 +7/5.7 - 5/5.7+.......+101/99.101 - 99/99.101
= 1- 1/3 + 1/3 -1/5 +1/5 -1/7+.....+1/99 - 1/101
= 1- 1/101=100/101
vay 2/1.3 +2/3.5+2/5.7+........+2/99.101=100/101
1.
a) tap hop cac diem doan thang BD va B, C,D tap hop cac diem thuoc ko doan thang BD va A, E
b) cap duong thang song song la AB//DE
c) cac cap duong thang cat nhau la :
AB va AE cat nhau tai A
BA va BD cat nhau tai B
AE va BD cat nhau tai C
DEva DB cat nhau tai D
EA va ED cat nhau tai E
2.
Do dai cua doan thang AB la :
6 - 4 = 2(cm)
Do dai cua doan thang AM la :
2: 2= 1(cm)
Do dai cua doan thang OM la :
4+1=5(cm)
Vay 5cm
a) so sanh ba phan so , ta duoc
5/27< 2/9 < 1/3
vay trong mot gio , doi thu ba lam duoc it phan cong viec nhat , doi thu hai la duoc nhieu cong viec nhat
b) neu lam trung , ca ba doi lam duoc 5/27+ 2/9+1/3= 20/27( cong viec)
A) X-2/3=-5/12
X=-5/12 +2/3
X= -5/12+8/12
X= 3/12
X= 1/4
B)8/5: X=-2/3
X= 8/5: ( -2/3)
X= 8/5( 3/-2)
X=-12/5
C)1-3/7. X=-2/7
3/7. X=1-(-2/7)
3/7.X=9/7
X= 9/7: 3/7
X= 9/7. 3/7
X=3
A)=-2/7+2/7x5/3
=-2/7+10/21
=-6/21+10/21
=4/21
B) -8/19+-4/21-17/21 +27/19
=-8/19+-4/21+1721+27/19
=(-8/19+27/19) +(-4/21 +-17/21)
= -8+27/19+(-4)+(-17)/21
= 19/19+-21/21
= 1-1=0
C)6/5x3/13 - 6/5x16/13
= 6/5x(3/13 - 16/13)
= 6/5 x (3-16/13)
=6/5x(-13/13)
= 6/5x ( -1)
= -6/5
