9/7 - 2/7 x 49/6 + 1/3
Bài 1: Tìm x :
a. ( x + 4 )2 - ( x + 1 ) ( x - 1 ) = 16
b. ( 2x - 1 )2 + ( x + 3 )2 - 5 ( x + 7 ) ( x - 7 ) = 0
c. ( x - 2 )3 - ( x - 3 ) ( x2 + 3x + 9 ) + 6 ( x + 1 )2 = 49
Bài 1: Tìm x :
a. ( x + 4 )2 - ( x + 1 ) ( x - 1 ) = 16
b. ( 2x - 1 )2 + ( x + 3 )2 - 5 ( x + 7 ) ( x - 7 ) = 0
c. ( x - 2 )3 - ( x - 3 ) ( x2 + 3x + 9 ) + 6 ( x + 1 )2 = 49
5) 6x – 5 = 3 + 4x 6) x – (17 – x) = x – 7
7) 9 – 25 = (7 – x) – ( 25 + 7) 8) 10 – 2.(4 – 3x) = - 4
9) (-12)2
.x = 56 + 10. 13x 10) 2x2
– 1 = 49
2/3 + 3/4
9/4 + 3/5
5/24 + 1/4
3/15 - 5/35 18/27 - 2/6 37/12 - 3
11/9 x 3/22 7/13 x 13/7 4 x6/7
2/5 : 3/10 3/8 : 9/4 8/21 : 4/7
2/3 + 3/4=17/12
9/4 + 3/5=57/20
5/24 + 1/4=11/24
3/15 - 5/35=2/35 18/27 - 2/6=1/3 37/12 - 3=1/12
11/9 x 3/22=1/6 7/13 x 13/7=1 4 x6/7=24/7
2/5 : 3/10=4/3 3/8 : 9/4=1/6 8/21 : 4/7=2/3
2/3 + 3/4
= 17/12
9/4 + 3/5
= 57/20
5/24 + 1/4
=11/24
3/15 - 5/35
=2/35
18/27 - 2/6
=1/3
37/12 - 3
= 1/12
11/9 x 3/22
=1/6
7/13 x 13/7
=1
4 x6/7
=24/7
2/5 : 3/10
=4/3
3/8 : 9/4
=1/6
8/21 : 4/7
= 2/3
1=17/12
2=57/20
3=11/24
4=2/35 7=1/3 10=1/12
5=1/6 8=1 11=24/7
6=4/3 9=1/6 12=2/3
Ai xong kết bạn nhé
tính bằng cách thuận tiện
6 x 9 x 49/ 81 x 7 x 6
2/5 + 11/9 + 3/5 + 7/9
2/5+11/9+3/5+7/9= (2/5+3/5)+(11/9+7/9) = 1+2 = 3
Viết các biểu thức sau dưới dạng một lũy thừa:
6, 3/2 x 9/4 x 81/16
7, (1/2)^7 x 8 x 32 x 2^8
8, (-1/7)^4 x 125 x 5
9, 4 x 32 : (2^3 x 1/16)
10, (1/7)^2 x 1/7 x 49
6:=(3/2)*(3/2)^2*(3/2)^4=(3/2)^7
7: =(1/2)^7*2^3*2^5*2^8=2^9
8: =(-1/7)^4*5^4=(-5/7)^4
9: =2^2*2^5:(2^3/2^4)
=2^7/2=2^6
10: =(1/7)^3*7^2=1/7
Tính nhẩm:
7 x 8 = ..... 16 : 2 = ..... 36 : 6 = ..... 49 : 7 = .....
2 x 5 = ..... 72 : 8 = ..... 9 x 3 = ...... 63 : 7 = .....
6 x 4 = ..... 25 : 5 = ..... 4 x 8 = ...... 7 x 5 = ......
7 x 8 = 56 16 : 2 = 8 36 : 6 = 6 49 : 7 = 7
2 x 5 = 10 72 : 8 = 9 9 x 3 = 27 63 : 7 = 9
6 x 4 = 24 25 : 5 = 5 4 x 8 = 32 7 x 5 = 35
7 x 8 = 56
2 x 5 = 10
6 x 4 = 24
16 : 2 = 8
72 : 8 = 9
25 : 5 = 5
36 : 6 = 6
9 x 3 = 27
4 x 8 = 32
49 : 7 = 7
63 : 7 = 9
7 x 5 = 35
1.so sánh
1/2:2/3......2/3:1/2 4/7:2/5......4/7:3/5
4/15:4/7......2/5x10/3 5/6......15/18-11/18
2.viết số thích hợp vào ô trống
2/3=..../18 7/9=49/.... ..../5=18/15
..../3=10/15 5/9=..../45 49/56=7/....
6/8=42/.... 2/9=..../63 49/56=..../8
`1)1/2:2/3 .... 2/3 : 1/2`
`=>1/2xx3/2 .... 2/3xx2`
`=>3/4 .... 4/3`
Vì `3/4 < 1` và `4/3>1`
`=>3/4<4/3`
__
`4/7:2/5 ... 4/7 : 3/5`
`=>4/7xx5/2....4/7xx5/3`
`=>20/14...20/21`
`=>10/7...20/21`
Vì `10/7>1` và `20/21<1`
`=>10/7>20/21`
__
`4/15:4/7....2/5xx10/3`
`=>4/15xx7/4...20/15`
`=>7/15...20/15`
Vì `7<20` nên `7/15<20/15`
__
`5/6...15/18-11/18`
`=>5/6...4/18`
Ta có : MSC : `18`
`5/6 = 15/18`
Vì `15>4` nên `5/6 > 4/18`
`2)2/3=(2xx6)/(3xx6)=12/18`
`7/9=(7xx7)/(9xx7)=49/63`
`6/5=(6xx3)/(5xx3)=18/15`
`2/3=(2xx5)/(3xx5)=10/15`
`5/9=(5xx5)/(9xx5)=25/45`
`49/56=(49:7)/(56:7)=7/8`
`6/8=(6xx7)/(8xx7)=42/56`
`2/9=(2xx7)/(9xx7)=14/63`
`49/56=(49:7)/(56:7)=7/8`
tính bằng cách thuận tiện
6 x 9 x 49/ 81 x 7 x 6
2/5 + 11/9 + 3/5 + 7/9