Thực hiện phép tính
a.7 5/9-(2 3/4+3 5/9)
b.(3/5×-7/10+2/10×3/5)÷(-3)
Thực hiện phép tính
a)-3/5 + 1/4 + -3/10
b)1/5 + -9/10 + -7/25
c)31/23 - ( 7/32 + 8/23 )
a: =-12/20+5/20-6/20
=-13/20
b: =10/50-45/50-14/50
=-49/50
c: =31/23-7/32-8/23=1-7/32=25/32
`a)-3/5 + 1/4 + -3/10= (-12)/20 + 5/20 + (-6)/20 = -13/20`
`b)1/5 + -9/10 + (-7/25)= 10/50 + (-45)/50 + (-14)/50 = (-49)/50`
`c)31/23 - ( 7/32 + 8/23 )= 31/23 - 417/736 =992/736 - 417/736 = 575/736=25/32 `
bài 1:thực hiện phiép tính
a)\(\dfrac{7}{4}\)+\(\dfrac{3}{2}\)+\(\dfrac{-9}{16}\)
b)\(\dfrac{-2}{7}\)+\(\dfrac{3}{5}\)+\(\dfrac{9}{7}\)+\(\dfrac{-18}{5}\)
c)\(\left\{-\dfrac{5}{13}\right\}\)+\(\dfrac{11}{10}\)-\(\dfrac{-9}{10}\)+\(\dfrac{-8}{13}\)
bài 2:tìm x biết
a)\(\dfrac{2}{9}\)-x=\(\dfrac{-5}{9}\)
b)x+\(\dfrac{-7}{13}\)=\(\dfrac{1}{2}\)
2:
a: 2/9-x=-5/9
=>x=2/9+5/9=7/9
b: x-7/13=1/2
=>x=1/2+7/13=27/26
câu a
\(\dfrac{7}{4}+\dfrac{3}{2}+\dfrac{-9}{16}\\ =\dfrac{28}{16}+\dfrac{24}{16}-\dfrac{9}{16}=\dfrac{43}{16}\)
câu b
\(-\dfrac{2}{7}+\dfrac{3}{5}+\dfrac{9}{7}+\dfrac{-18}{5}\\ =-\dfrac{10}{35}+\dfrac{21}{35}+\dfrac{45}{35}-\dfrac{126}{35}\\ =-\dfrac{70}{35}=-2\)
câu c
\(-\dfrac{5}{13}+\dfrac{11}{10}-\dfrac{-9}{10}+\dfrac{-8}{13}\\ =-\dfrac{5}{13}+\dfrac{11}{10}+\dfrac{9}{10}-\dfrac{8}{13}\\ =-\dfrac{50}{130}+\dfrac{143}{130}+\dfrac{117}{130}-\dfrac{80}{130}\\ =\dfrac{130}{130}=1\)
bài 2
câu a
\(\dfrac{2}{9}-x=-\dfrac{5}{9}\\ x=\dfrac{2}{9}-\dfrac{-5}{9}\\ x=\dfrac{7}{9}\)
câu b
\(x+\dfrac{-7}{13}=\dfrac{1}{2}\\ x=\dfrac{1}{2}-\dfrac{-7}{13}\\ x=\dfrac{13}{26}+\dfrac{14}{26}\\ x=\dfrac{17}{26}\)
Câu 1: Thực hiện phép tính
a, \(\dfrac{7}{9}-\dfrac{16}{9}\)
b, \(\dfrac{2}{-15}+\dfrac{7}{10}\)
c, \(\left(4\dfrac{2}{3}-4\dfrac{3}{4}\right):\dfrac{-5}{12}-\dfrac{4}{5}\)
d, \(\dfrac{-141}{157}.\dfrac{23}{59}-\dfrac{141}{157}.\dfrac{36}{59}+\dfrac{16}{-157}\)
a. 7/9 - 16/9 = -9/9 = -1
b. 2/-15 + 7/10 = 17/30
c. (4 2/3 - 4 3/4) : -5/12 - 4/5
= (14/3 - 19/4) : (-5/12) - 4/5
= -1/12 : (-5/12) - 4/5
= 1/5 - 4/5
= -3/5
* Thực hiện phép tính
a, A= \(\sqrt{12-3\sqrt{7}}-\sqrt{12+3\sqrt{7}}\)
b, B= \(\sqrt{4+\sqrt{10+2\sqrt{5}}}+\sqrt{4-\sqrt{10+2\sqrt{5}}}\)
c, C= \(\sqrt{3-\sqrt{5}}+\sqrt{3+\sqrt{5}}\)
c: Ta có: \(C=\sqrt{3-\sqrt{5}}+\sqrt{3+\sqrt{5}}\)
\(=\dfrac{\sqrt{6-2\sqrt{5}}+\sqrt{6+2\sqrt{5}}}{\sqrt{2}}\)
\(=\dfrac{\sqrt{5}-1+\sqrt{5}+1}{\sqrt{2}}=\sqrt{10}\)
Bài 1: Thực hiện phép tính
a) \(1-\dfrac{1}{2}+\dfrac{1}{3}\)
b) \(\dfrac{2}{5}+\dfrac{3}{5}:\dfrac{9}{10}\)
c) \(\dfrac{7}{11}.\dfrac{3}{4}+\dfrac{7}{11}.\dfrac{1}{4}+\dfrac{4}{11}\)
d) \(\left(\dfrac{3}{4}+0,5+25\%\right).2\dfrac{2}{3}\)
\(Bài 2:\text{Tìm x}\)
a) \(x+\dfrac{1}{2}=2\)
b) \(75\%x-\dfrac{1}{2}=-1\dfrac{1}{4}\)
c) \(\left|x-\dfrac{2}{5}\right|+\dfrac{7}{10}=3\)
a) \(1-\dfrac{1}{2}+\dfrac{1}{3}=\dfrac{6}{6}-\dfrac{3}{6}+\dfrac{2}{6}=\dfrac{6-3+2}{6}=\dfrac{1}{6}\)
\(b.\) \(\dfrac{2}{5}+\dfrac{3}{5}:\dfrac{9}{10}=\dfrac{2}{5}+\dfrac{3}{5}.\dfrac{10}{9}=\dfrac{2}{5}+\dfrac{2}{3}=\dfrac{6}{15}+\dfrac{10}{15}=\dfrac{6+10}{15}=\dfrac{16}{15}\)
\(c.\) \(\dfrac{7}{11}.\dfrac{3}{4}+\dfrac{7}{11}.\dfrac{1}{4}+\dfrac{4}{11}=\dfrac{21}{44}+\dfrac{7}{44}+\dfrac{4}{11}=\dfrac{21}{44}+\dfrac{7}{44}+\dfrac{16}{44}=\dfrac{21+7+16}{44}=\dfrac{44}{44}=1\)
a/\(1-\dfrac{1}{2}+\dfrac{1}{3}=\dfrac{6}{6}-\dfrac{3}{6}+\dfrac{2}{6}=\dfrac{5}{6}\)
b/\(\dfrac{2}{5}+\dfrac{3}{5}:\dfrac{9}{10}=\dfrac{2}{5}+\dfrac{3}{5}.\dfrac{10}{9}=\dfrac{2}{5}+\dfrac{2}{3}=\dfrac{6}{15}+\dfrac{10}{15}=\dfrac{16}{15}\)
d) \(\left(\dfrac{3}{4}+0,5+25\%\right).2\dfrac{2}{3}=\left(\dfrac{3}{4}+\dfrac{1}{2}+\dfrac{1}{4}\right).\dfrac{8}{3}=\left(\dfrac{3}{4}+\dfrac{2}{4}+\dfrac{1}{4}\right).\dfrac{8}{3}=\dfrac{3}{2}.\dfrac{8}{3}=4\)
Dạng 1: RÚT GỌN
Bài 1: Thực hiện phép tính:
a,
12 5 6 2 10 3 5 2
2 6 3 9 3
2 .3 4 .9 5 .7 25 .49
(2 .3) (125.7) 5 .14
b,
18 7 3 15 15
10 15 14 13
2 .18 .3 3 .2
2 .6 3 .15.4
c,
6 5 9
4 12 11
4 .9 6 .120
8 .3 6
Bài 2: Thực hiện phép tính:
a,
15 9 20 9
29 16 29 6
5.4 .9 4.3 .8
5.2 .9 7.2 .27
b,
4 2 2
3 3 2
2 .5 .11 .7
2 .5 .7 .11
c,
11 12 11 11
12 11 11 11
5 .7 5 .7
5 .7 9.5 .7
Bài 3: Thực hiện phép tính:
a,
22 7 15
14 2
11.3 .3 9
(2.3 )
b,
10 10 10 9
9 10
2 .3 2 .3
2 .3
c,
5 4 9
10 8 8
4 .9 2.6
2 .3 6 .20
Bài 4: Thực hiện phép tính:
a,
12 5 6 2 10 3 5 2
2 6 4 5 3 9 3
2 .3 4 .9 5 .7 25 .49
(2 .3) 8 .3 (125.7) 5 .14
b,
15 9 20 9
9 19 29 6
5.4 .9 4.3 .8
5.2 .6 7.2 .27
c,
5 4 9
10 8 8
4 .9 2.6
2 .3 6 .20
Bài 5: Thực hiện phép tính:
a,
12 7 15 8
24 14 12 5
15.4 .9 4.3 .8
19.2 .3 6.4 .27
b,
15 22 16 4
9 7 5 23
3 .2 6 .4
2.9 .8 7.27 .2
c,
3 10 9
6 12 11
16 .3 120.6
4 .3 6
Bài 6: Thực hiện phép tính :
a,
12 5 6 2 10 3 5 2
6 3 2 4 5 9 3
2 .3 4 .9 5 .7 25 .49
2 .3 8 .3 125.7 5 .14
A
b,
15 9 20 9
10 12 29 6
5.4 .9 4.3 .8
5.2 .6 7.2 .27
Bài 7: Thực hiện phép tính:
a,
12 5 6 2
6
2 4 5
2 .3 4 .9
2 .3 8 .3
A
b,
5 4 9
10 8 8
4 .9 2.6
2 .3 6 .20
B
Bài 8: Thực hiện phép tính :
a,
10 10
9 4
3 .11 3 .5
3 .2
b,
10 10
8
2 .13 2 .65
2 .104
Bài 9: Thực hiện phép tính:
a,
30 7 13 27
27 7 10 27
2 .5 2 .5
2 .5 2 .5
b,
6 6 5 3
10 5 3
3 .15 9 . 15
3 .5 .2
Bài 10: Thực hiện phép tính:
a,
2 11 2 2 6 2
12 4 2 3
5 .6 .16 6 .12 .15
2.6 .10 81 .960
b,
9
19 3 4
10 9 10
2 .27 .5 15. 4 .9
6 .2 12
A
2
Bài 11: Thực hiện phép tính:
a,
5
15 4 10 20
6 6 3 15
0,8 2 .9 45 .5
:
0,4 6 .8 75
b,
15 14 22 21
10 16 15
5 3.7 19.7 2.5 9.5
:
25 7 3.7
A
Bài 12: Tính giá trị của biểu thức:
7 3 3
7
7 7
2 9 3 .5 :
5 4 16
2 .5 512
A
Bài 13: Tính biểu thức:
3 3 1 0,6 1 0,875 0,7 14 7 13 6 2 1,21 :
25 6 6 1 1,2 0,25 0,2
7 13 3
B
(Chưa làm)
Bài 14: Tính biêu thức:
3 6
3
2
1 1 1 3 .12 84 51. 37 51. 137
3 4 7 27.4
A
Bài 15: Thực hiện phép tính:
a, 1024: 5 5 (17.2 15.2 ) b, 3 0 3 5 .2 (23 4 ) : 2 c, 5 4 2 (5.3 17.3 ) : 6
Bài 16: Thực hiện phép tính:
a, 2 2 2 2 2 (10 11 12 ) : (13 14 ) b, 3 4 3 2 2 (2 .9 9 .45) : (9 .10 9 )
Bài 17: Thực hiện phép tính:
a, 14 14 16 4 (3 .69 3 .12) : 3 7 : 2 b, 4 4 12 12 24 : 3 32 :16
Bài 18: Thực hiện phép tính :
a,
2010 10 8 4 2010 2010 2010 7 : 7 3.2 2 : 2 b,
100 101 102 97 98
1.Thực hiện phép tính
a) \(\dfrac{4}{5}\) + \(\dfrac{6}{5}\) : \(\dfrac{7}{15}\) - \(\dfrac{3}{7}\)
b) \(\dfrac{9}{13}\) . \(\dfrac{5}{3}\) + \(\dfrac{-6}{13}\) .\(\dfrac{9}{13}\) - \(\dfrac{9}{13}\) . \(\dfrac{20}{13}\)
2.Tìm x,biết:
a) \(\dfrac{2}{5}\) . x - \(\dfrac{1}{3}\) = 1\(\dfrac{2}{3}\)
b) \(\dfrac{4}{9}\) - \(\dfrac{5}{9}\) : x = \(\dfrac{7}{3}\)
c) \(\dfrac{4}{5}\) . x + \(\dfrac{-7}{3}\) . x = \(\dfrac{\left(-2\right)^3}{5}\)
Bài 1: tính
a. 1/3-(-1và2/5)+(-3và1/4)
b.5/4-(-3và1/2)-7/10
c.3/2-[(-4/7)-(1/2+5/8)]
Bài 2: thực hiện phép tính bằng cách hợp lý
a. A=(1/2-7/13-1/3)+(-6/13+1/2+1và1/3)
b.B=0,75+2/5+(1/9-1và1/2+5/4)
c.(-5/9).3/11+(-13/18).3/11
d.(-2/3).3/11+(-16/9).3/11
e.(-1/4).(-2/13)-7/24.(-2/13)
f.(-1/27).3/7+(5/9).(-3/7)
g.(-1/5+3/7):2/11+(-4/5+4/7):2/11
bài 3: thực hiện phép tính
a.0,3-4/9:4/3.6/5+1
b.1+2:(2/3-1/6).(-2,25)
c.[(1/4-0,5).2+8/3]:2
d.[(3/8-5/12).6+1/3].4
e.(4/5-1):3/5-2/3.0,5
f.0,8:{0,2-7.[1/6+(5/21-5/14)]}
Bài 4: tính theo cách hợp lý
a.4/15-(2,9-11/15)
b.(-36,75)+(37/10-63,25)-(-6,3)
c. 6,5+(-10/17)-(-7/2)-7/17
d.(-39,1).13/25-60,9.13/25
e. -5/12-3,7-7/12-6,3
f.2,8.-6/13-7,2-2,8.7/13
4:
a: =4/15-2,9+11/15=1-2,9=-1,9
b: \(=-36,75+3,7-63,25+6,3=10-100=-90\)
c: \(=6,5+3,5-\dfrac{10}{17}-\dfrac{7}{17}=10-1=9\)
d: \(=\dfrac{13}{25}\left(-39,1-60,9\right)=\dfrac{13}{25}\left(-100\right)=-52\)
e: =-5/12-7/12-3,7-6,3=-1-10=-11
f: =2,8(-6/13-7/13)-7,2=-2,8-7,2=-10
Thực hiện phép tính :
a, 4/5 ( 1/2 - 7/4 ) - 3/4 ( 1/3 - 8/12 ) + 15/4 : -5/8 - 6/5 : 1/10
b, [ -5/9 ] ( 1/5 - 11/10 ) : 3/2 - 3/4 ( 7/6 - 1/3 ) + 28/5 : -7/10