13 x 5 = ?
9 x ? = 45
8 x ? = 80
100 : ? = 2
1. -2/9 x 15/17 + -2/9 x 2/17
2. -5/3 x 6/5 + -7/9 x 3/10
3. 15/20 x 7/5 + -9/7 x -6/4
4.-25/13 x 5/19 + -25/13 x 14/19
5 -7/13 x 13/5 + -9/7 x 5/3
6. 27/35 x 5/9 - 2/7 x -7/5
7. 10/13 x 13/5 + {-9/5} x 10/3
8. 100/27 x 9/20 + 40% x 5/3
9. 1,5 x 5/12 + 1/4 x 3/4
10. 2 1/2 x 7/5 + {-9/10} x 2/3
11. X + 45% = 2 1/2 -5/3
12. 80% + X = -5/2 + 3/4
13. 4/25 - X =-5/2 + -3/10
1: =-2/9(15/17+2/17)=-2/9
2: \(=\dfrac{-6}{3}+\dfrac{-21}{90}\)
=-2-7/30=-67/30
3: \(=\dfrac{3}{4}\cdot\dfrac{7}{5}+\dfrac{9}{7}\cdot\dfrac{3}{2}\)
=21/20+27/14=417/140
4: =-25/13(5/19+14/19)=-25/13
5: =-7/5-45/21=-7/5-15/7=-124/35
1: =-2/9(15/17+2/17)=-2/9
2: =34⋅75+97⋅32=34⋅75+97⋅32
=21/20+27/14=417/140
4: =-25/13(5/19+14/19)=-25/13
5: =-7/5-45/21=-7/5-15/7=-124/35
1. -2/9 x 15/17 + -2/9 x 2/17
2. -5/3 x 6/5 + -7/9 x 3/10
3. 15/20 x 7/5 + -9/7 x -6/4
4.-25/13 x 5/19 + -25/13 x 14/19
5 -7/13 x 13/5 + -9/7 x 5/3
`1, -2/9 xx 15/17 + (-2/9) xx 2/17`
`= -2/9 xx (15/17 + 2/17)`
`= -2/9 xx 17/17`
`=-2/9xx1`
`=-2/9`
__
`-5/3 xx 6/5 + (-7/9) xx 3/10`
`= -30/15 + (-21/90)`
`= -2 + (-7/30)`
`=-60/30 +(-7/30)`
`=-67/30`
__
`15/20 xx 7/5 + (-9/7) xx (-6/4)`
`=3/4 xx7/5 + (-9/7) xx(-6/4)`
`= 21/20 + 54/28`
`= 21/20 + 27/14`
`=417/140`
__
`-25/13 xx 5/19 + (-25/13) xx 14/19`
`=-25/13 xx (5/19 +14/19)`
`=-25/13 xx 19/19`
`= -25/13 xx 1`
`=-25/13`
__
`-7/13 xx 13/5 + (-9/7) xx 5/3`
`=-7/5 +(-15/7)`
`=-124/35`
Tìm x, biết:
a. 5/(x+1).(x+6)+3/(x+6).(x+9)+4/(x+9).(x+13)=x/(x+1).(x+13)
( Với x khác -1, x khác -6, x khác -9,x khác -13)
b. 2/(x-2).(x-5)+4/(x-5).(x-9)+6/(x-9).(x-15)-1/x-15=3/4
( Với x khác 2, x khác 5, x khác 9, x khác 15)
Tính giá trị biểu thức :
458 - 123 x 13 +45
458 - 123 x 13 + 45
= 458 - 1599 + 45
= (-1141) + 45
= - 1096
Tim x
x/13=35/91
9+x/13-x=5/6
x+x:5*7,5+x:2*9=315
2/3*x+1/2=9/10-1/5
Tính:
a) 2^5 x 13^12 x 7^8 : 27 x 13^10 x 7^9
b) 2^n x 11 x 3 : 6^n x 3
c) 5^5 x 7 x 9^5 : 15^10
d) 7 x 8^10 x 27^9 - 8 x 9^13 x 2^27 : 7 x 6^26 x 2^2 - 2^4 x 8^3 x 27^9
e) 2^2^1^2015
f) 2015^0^2015^0^2015
tính nhanh : 3/5 x 7/9 + 11/9 x 3/5 - 3/10
14/13 : 1/2 + 3/13 x 2 - 2 x 7/13
sao ko quan tâm
6. 27/35 x 5/9 - 2/7 x -7/5
7. 10/13 x 13/5 + {-9/5} x 10/3
8. 100/27 x 9/20 + 40% x 5/3
9. 1,5 x 5/12 + 1/4 x 3/4
9: =3/2*5/12+3/16
=15/24+3/16
=5/8+3/16
=13/16
Tìm x :
X + 5/9 = 4/3 X - 4/9 = 1/2 6/13 + X = 7/6 13/5 - X = 5/6
Giúp mình ạ !
X + 5/9 = 4/3
X = 4/3 - 5/9
X = 7/9
X - 4/9 = 1/2
X = 1/2 + 4/9
X = 17/18
6/13 + X = 7/6
X = 7/6 - 6/13
X = 55/78
13/5 - X = 5/6
X = 13/5 - 5/6
X= 53/30
X + 5/9 = 4/3
x = 4/3 - 5/9
x = 7/9
X - 4/9 = 1/2
x = 1/2 + 4/9
x = 17/18
6/13 + X = 7/6
x = 7/6 - 6/13
x - 55/78
13/5 - X = 5/6
x = 13/5 - 5/6
x = 53/30
5/9 x -2/13 + -5/13 x 11/9 - 4/9 ?
\(\frac{5}{9}.\frac{-2}{13}+\frac{5}{13}.\frac{11}{9}-\frac{4}{9}\)
\(=\frac{5}{9}.\frac{-2}{13}+\frac{5}{9}.\frac{-11}{13}-\frac{4}{9}\)
\(=\frac{5}{9}\left(\frac{-2}{13}+\frac{-11}{13}\right)-\frac{4}{9}\)
\(=\frac{5}{9}.-1-\frac{4}{9}\)
\(=\frac{-5}{9}-\frac{4}{9}\)
\(=-1\)
\(\frac{5}{9}\times\frac{-2}{13}+\frac{-5}{13}\times\frac{11}{9}-\frac{4}{9}\)
\(=\frac{2}{9}\times\frac{-5}{13}+\frac{-5}{13}\times\frac{11}{9}-\frac{4}{9}\)
\(=\frac{-5}{13}\times\left(\frac{2}{9}+\frac{11}{9}\right)-\frac{4}{9}\)
\(=\frac{-5}{13}\times\frac{13}{9}-\frac{4}{9}\)
\(=\frac{-5}{9}-\frac{4}{9}\)
\(=\frac{-9}{9}=-1\)