x - 3/8 = 3/10 + 4/5
6/7 . x = -11/7
(đăng cho các CTV thử việc ^-^)
Tìm x:
a, -5/6 - x = 7/12 + -1/3
b, (4,5 - 2x).(-1 4/7) = 11/14
c, (2/11 + 1/3).x = (1/7 - 1/8).56
`a)-5/6-x=7/12+[-1]/3`
`-5/6-x=1/4`
`x=-5/6-1/4`
`x=-13/12`
`b)(4,5-2x).(-1 4/7)=11/14`
`(4,5-2x).(-11/7)=11/14`
`4,5-2x=11/14:(-11/7)=-0,5`
`2x=4,5-(-0,5)=5`
`x=5:2=2,5`
`c)(2/11+1/3)x=(1/7-1/8).56`
`17/33 x=1/56 .56=1`
`x=33/17`
3 x ( 1/7 + 1/3 - 3/14 ) : 11/14
( 8/5 + 11/5 ) x 11/10 + ( 17/10 - 4/5) : 3/7
a: \(=3\cdot\dfrac{6+14-9}{42}\cdot\dfrac{14}{11}\)
\(=3\cdot\dfrac{11}{42}\cdot\dfrac{14}{11}=1\)
b: \(=\dfrac{19}{5}\cdot\dfrac{11}{10}+\dfrac{9}{5}\cdot\dfrac{7}{3}\)
\(=\dfrac{209}{50}+\dfrac{63}{15}=4.18+4.2=8,38\)
câu 1. tính giá trị các biểu thức sau:
a, 8.(-5).(-4).2 b, 1 3/7 + (-1/3 + 2 4/7) c, 8/5.2/3 + -5.5/3.5 d, 6/7+5/8 :5 - 3/16(-2)^2
câu 2.tìm x, biết:
a, 2x + 10=16 b, x - 1/3 = 5/4 c,2.x+3 1/3= 7 1/3 d,(2/11+1/3).x=(1/7-1/8).56
GIÚP VS! MAI TUI PHẢI NỘP RỒI! HELP ME
Câu 1 :
a, 8.( -5 ).( -4 ).2
= [ 8.2 ].[( -5 ).(-4 ]
= 16.20
= 320
b, \(1\frac{3}{7}+\frac{-1}{3}+2\frac{4}{7}\)
\(=\frac{10}{7}+\frac{-1}{3}+\frac{18}{7}\)
\(=\frac{11}{3}\)
c, \(\frac{8}{5}.\frac{2}{3}+\frac{-5.5}{3.5}\)
\(=\frac{8}{3}+\frac{-5}{3}\)
\(=\frac{3}{3}=1\)
d, \(\frac{6}{7}+\frac{5}{8}:5-\frac{3}{16}.\left(-2\right)^2\)
\(=\frac{6}{7}+\frac{1}{8}-\frac{3}{16}.4\)
\(=\frac{55}{56}-\frac{3}{4}\)
\(=\frac{13}{56}\)
Câu 2 :
a, 2x + 10 = 16
2x = 16 + 10
2x = 26
x = 26 : 2
x = 13
b, \(x-\frac{1}{3}=\frac{5}{4}\)
\(x=\frac{5}{4}+\frac{1}{3}\)
\(x=\frac{19}{12}\)
c, \(2x+3\frac{1}{3}=7\frac{1}{3}\)
\(2x+\frac{10}{3}=\frac{22}{3}\)
\(2x=\frac{22}{3}-\frac{10}{3}\)
\(2x=4\)
\(x=4:2\)
\(x=2\)
d, \(\left(\frac{2}{11}+\frac{1}{3}\right)x=\left(\frac{1}{7}-\frac{1}{8}\right).56\)
\(\frac{17}{33}x=1\)
\(x=1-\frac{17}{33}\)
\(x=\frac{16}{33}\)
Tính bằng cách thuận tiện nhất:
a) 16, 2 x 3, 7 + 5, 7 x 16, 2 - 7, 8 x 4, 8 - 4, 6 x 7, 8 : 11, 2 + 12, 3 + 13, 4 - 12, 6 - 11, 5 - 10, 4
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
BÀI 3: TÍNH BẰNG CÁCH THUẬN TIỆN NHẤT
245 x 11 + 11 x 365 78 x 75 + 75 x 89 + 75 x 123 2 x 250 x 50 x 8
(76 : 7) x 4 (372 x 15) x 9 (56 x 23 x 4) : 7
Bài 1:
a) 8/7 - 5/11 : 8 b) 1 + 2/9 : 7/3 - 10/7 c) 11/3 - 2 : 7/3 + 4
Bài 2:
a) 9/4 - x = 5/11 : 1/2 b) 2/9 : x = 7/3 - 10/7
Bài 3:
\(\dfrac{1999x1998-1}{1997x1999+1998}\)
1:
a: =8/7-5/88=669/616
b: \(=1+\dfrac{2}{9}\cdot\dfrac{3}{7}-\dfrac{10}{7}=1+\dfrac{2}{21}-\dfrac{10}{7}\)
\(=\dfrac{21+2-30}{21}=\dfrac{-7}{21}=\dfrac{-1}{3}\)
c: \(=\dfrac{11}{3}-\dfrac{6}{7}+4=\dfrac{77-18+84}{21}=\dfrac{143}{21}\)
Bài 2:
a: =>9/4-x=5/11*2=10/11
=>x=9/4-10/11=59/44
b: =>2/9:x=19/21
=>x=2/9:19/21=14/57
a .(18 – 9 x 2) x (2 + 4 + 6 + 8 + 10)
b.(7 x 8 – 56 ) : (2 + 4 + 6 + 8 + 112)
c. (2 + 125 + 6 + 145 + 112) x (42 – 6 x 7)
d.(12 x 6 – 12 x 4 – 12 x 2) x ( 347 + 125)
e(a x 7 + a x 8 – a x 15) : (1 + 2 + 3 + ........ + 10)
f.58 – 58 x (6 + 54 – 60)
g.32 + 63 x a x ( a x 1 – a : 1) + 32 x 8 + 32
h.(1 + 2 + 3 + 4 + .... + 9) x (21 x 5 – 21 – 4 x21)
i.(9 x 7 + 8 x 9 – 15 x 9) : (1 + 3 + 5 + 7 + ........+ 17 + 19)
k.(2 + 4 + 6 + 8 + ... + 20) x (56 x 3 – 72 : 9 x 21)
1.(18 - 18) x (2 + 8) + ( 4 + 6) + 10 = 30
có rút gọn phân số 35/6 về phân số đc ko ? Nếu có thì mn rút gọn cho mik nhé !
Ai xong tr tui k cho
Tính nhẩm
9 x 5 =
63 : 7 =
8 x 8 =
5 x 7 =
8 x 7 =
3 x 8 =
40 : 5 =
5 x 5 =
7 x 5 =
7 x 8 =
6 x 4 =
45 : 9 =
7 x 7 =
35 : 5 =
56 : 8 =
2 x 8 =
81 : 9 =
9 x 9 =
35 : 7 =
56 : 7 =
9 x 5 = 45
63 : 7 = 9
8 x 8 = 64
5 x 7 = 35
8 x 7 =56
3 x 8 = 24
40 : 5 = 8
5 x 5 = 25
7 x 5 = 35
7 x 8 =56
6 x 4 = 24
45 : 9 = 5
7 x 7 = 49
35 : 5 = 7
56 : 8 = 7
2 x 8 = 16
81 : 9 = 9
9 x 9 = 81
35 : 7 = 5
56 : 7 = 8
ay bạn ơi dễ vậy mà