Tính hợp lí
a) 7/-25+ -18/25+ 4/23+ 5/7+ 19/23
b) 7/19 x 8/11 + 7/19 x 3/11+ 12/19
Nhanh lên, mk đg cần gấp
Tính hợp lí
a) 7/-25+ -18/25+ 4/23+ 5/7+ 19/23
b) 7/19 x 8/11 + 7/19 x 3/11+ 12/19
Nhanh lên, mk đg cần gấp
\(a,\dfrac{7}{-25}+\dfrac{-18}{25}+\dfrac{4}{23}+\dfrac{5}{7}+\dfrac{19}{23}\)
\(=\left(\dfrac{-7}{25}+\dfrac{-18}{25}\right)+\left(\dfrac{4}{23}+\dfrac{19}{23}\right)+\dfrac{5}{7}\)
\(=\left(-1\right)+1+\dfrac{5}{7}\)
\(=0+\dfrac{5}{7}=\dfrac{5}{7}\)
b, \(\dfrac{7}{19}.\dfrac{8}{11}+\dfrac{7}{19}.\dfrac{3}{11}+\dfrac{12}{19}\)
\(=\dfrac{7}{19}\left(\dfrac{8}{11}+\dfrac{3}{11}\right)+\dfrac{12}{19}\)
\(=\dfrac{7}{19}.1+\dfrac{12}{19}\)
\(=\dfrac{7}{19}+\dfrac{12}{19}=1\)
a. \(\dfrac{7}{-25}+\dfrac{-18}{25}+\dfrac{4}{23}+\dfrac{5}{7}+\dfrac{19}{23}\)
\(=\left(\dfrac{-7}{25}+\dfrac{-18}{25}\right)+\left(\dfrac{4}{23}+\dfrac{19}{23}\right)+\dfrac{5}{7}\)
\(=-1+1+\dfrac{5}{7}\)
\(=\dfrac{5}{7}\)
b. \(\dfrac{7}{19}\cdot\dfrac{8}{11}+\dfrac{7}{19}\cdot\dfrac{3}{11}+\dfrac{12}{19}\)
\(=\dfrac{7}{19}\left(\dfrac{8}{11}+\dfrac{3}{11}\right)+\dfrac{12}{19}\)
\(=\dfrac{7}{19}\cdot1+\dfrac{12}{19}\)
\(=\dfrac{7}{19}+\dfrac{12}{19}\)
\(=1\)
a. \(\dfrac{7}{-25}+\dfrac{-18}{25}+\dfrac{4}{23}+\dfrac{5}{7}+\dfrac{19}{23}\)
= \(\left(\dfrac{7}{-25}+\dfrac{-18}{25}\right)+\left(\dfrac{4}{23}+\dfrac{19}{23}\right)+\dfrac{5}{7}\)
= \(\left(-1\right)+1+\dfrac{5}{7}\)
= \(0+\dfrac{5}{7}=\dfrac{5}{7}\)
b. \(\dfrac{7}{19}.\dfrac{8}{11}+\dfrac{7}{19}.\dfrac{3}{11}+\dfrac{12}{19}\)
= \(\dfrac{7}{19}.\left(\dfrac{8}{11}+\dfrac{3}{11}\right)+\dfrac{12}{19}\)
= \(\dfrac{7}{19}.1+\dfrac{12}{19}\)
= \(\dfrac{7}{19}+\dfrac{12}{19}=1\)
tính
a, 7/-25 + -18/25 + 4/23 +5/7+19/23
b, 7/19 x 8 /11 + 7/19 x 3/11 + 12/19
c ,day la hon so nha: 8 2/7 -(3 4/7 + 4 2/7 )
d, -7/9 .3/11 + -7 /9.8/11 + 1 7/9
giúp mình bài này với
bạn nam đọc 1 quyển sách trong 3 ngày . ngày 1 đọc 1 phần 3 số trang . ngày thứ 2 đọc 2 phần 5 số trang còn lại .ngày 3 đọc 36 trang còn lại. hỏi quyển sách có bao nhiêu trang
mình giúp bạn thì bạn giúp mình nhé
Thực hiện phép tính:
a. 7/-25 + -18/25 + 4/23 + 5/7 + 19/23
b. -2 + 15/19 + -15/17 +15/23 + 4/19
c. -5/11 + [-6/11 +1]
d. 1,4 . 15/49 - [4/5 + 2/3] : hai một phần năm
e. 7/19 .8/11 + 7/19 . 3/11 + 12/19
\(\dfrac{7}{-25}+\dfrac{18}{25}+\dfrac{4}{23}+\dfrac{5}{7}+\dfrac{19}{23}\)
=\(\left(\dfrac{-7}{25}+\dfrac{18}{25}\right)+\left(\dfrac{4}{23}+\dfrac{19}{23}\right)+\dfrac{5}{7}\)
= \(\dfrac{11}{25} +1+\dfrac{5}{7}\)
= \(1\dfrac{11}{25}+\dfrac{5}{7}\)
= \(2\dfrac{27}{175}\)
b) \(-2+\dfrac{15}{19}+\dfrac{-15}{17}+\dfrac{15}{23}+\dfrac{4}{19}\)
=\(-2+\left(\dfrac{ }{ }\right)\)
4) so sánh hai phân số sau
a) 7/15 và 4/9
B1 tính nhanh nếu có thể
a) (-18).5+5.10+5.(-2)
b) (-15):(-5)+7.(-3/7)
c) (-157)+(-16)+257+(-43)+(-84)
d) (+23)+(-135)-(-77)-/-65/+(-30)
e) -5/7 + (-6/11+1)
f) 1/2-2/3+4/5-5/6
g)1/3.4/5+1/3.6/5+2/3
h) -5/7.2/11+-5/7.9/11+1 5/7 không phải 15 phần 7
I)19/5.2007/2017+19/5.10/2017
K) 4/25.5/9+-4/25.10/3+7/9
m) 7/19.8/11+7/19.3/11+12/19
n)17/13.18/23-4/13.18/23-(-5)/23
P) 5/7 .5/11+5/7.2/11-5/7.14/11
q)-2/17+15/19+-15/17+13/20+4/19
X)7/-25+-18/25+4/23+5/8+19/23
S)5/7.-4/19+-15/7.5/19
Tính
a) -19 - |+13| + |-10| - (-5) - 11
b) ( -10) - (11) + |-5| - |-7| - 8
c) - (-8) - (+7) - |-11| + |+12|
d) -14 - |-18| - (-20) - |-25|
đ) 23 - |-15| - (-17) + |-13|
Nhanh lên voeí ạ !
a) Ta có: \(-19-\left|+13\right|+\left|-10\right|-\left(-5\right)-11\)
\(=-19-13+10+5-11\)
\(=-28\)
b) Ta có: \(\left(-10\right)-\left(11\right)+\left|-5\right|-\left|-7\right|-8\)
\(=-10-11+5-7-8\)
\(=-31\)
c) Ta có: \(-\left(-8\right)-\left(+7\right)-\left|-11\right|+\left|+12\right|\)
\(=8-7-11+12\)
\(=2\)
d) Ta có: \(-14-\left|-18\right|-\left(-20\right)-\left|-25\right|\)
\(=-14-18+20-25\)
\(=-37\)
đ) Ta có: \(23-\left|-15\right|-\left(-17\right)+\left|-13\right|\)
\(=23-15+17+13\)
\(=38\)
bài 1
a. 5/18 + 8/19 - 7/21 + ( -10/36 + 11/19 + 1/3) - 5/8
b.1/13 + ( -5/18 - 1/13 + 12/17 ) - ( 12/17 - 5/18 + 7/5 )
c.15/14 - (17/23 - 80/87 + 5/4)+(17/23 - 15/14 + 1/4 )
d.1/25 - 4/27 + ( -23/27 + -1/25 - 5/43 ) + 5/43 - 4/7
bài 2
a. x +1/3 = 3/4
b. x - 2/5 = 5/7
c. -x - 2/3 = -6/7
d. 4/7 - x = 1/3
e. x+ 5/2 = -3/2
f. x + 5/6 = -1/12
GIÚP MÌNH VỚI Ạ MÌNH CẢM ƠN TRƯỚC
Bài 1:
a; \(\dfrac{5}{18}\) + \(\dfrac{8}{19}\) - \(\dfrac{7}{21}\) + (- \(\dfrac{10}{36}\) + \(\dfrac{11}{19}\) + \(\dfrac{1}{3}\)) - \(\dfrac{5}{8}\)
= \(\dfrac{5}{18}\) + \(\dfrac{8}{19}\) - \(\dfrac{1}{3}\) -\(\dfrac{10}{36}\) + \(\dfrac{11}{19}\) + \(\dfrac{1}{3}\) - \(\dfrac{5}{8}\)
= (\(\dfrac{5}{18}\) - \(\dfrac{10}{36}\)) + (\(\dfrac{8}{19}\) + \(\dfrac{11}{19}\)) - (\(\dfrac{1}{3}\) - \(\dfrac{1}{3}\)) - \(\dfrac{5}{8}\)
= (\(\dfrac{5}{18}\) - \(\dfrac{5}{18}\)) + \(\dfrac{19}{19}\) - 0 - \(\dfrac{5}{8}\)
= 0 + 1 - \(\dfrac{5}{8}\)
= \(\dfrac{3}{8}\)
b; \(\dfrac{1}{13}\) + (\(\dfrac{-5}{18}\) - \(\dfrac{1}{13}\) + \(\dfrac{12}{17}\)) - (\(\dfrac{12}{17}\) - \(\dfrac{5}{18}\) + \(\dfrac{7}{5}\))
= \(\dfrac{1}{13}\) - \(\dfrac{5}{18}\) - \(\dfrac{1}{13}\) + \(\dfrac{12}{17}\) - \(\dfrac{12}{17}\) + \(\dfrac{5}{18}\) - \(\dfrac{7}{5}\)
= (\(\dfrac{1}{13}\) - \(\dfrac{1}{13}\)) + (\(\dfrac{12}{17}\) - \(\dfrac{12}{17}\)) + (-\(\dfrac{5}{18}\) + \(\dfrac{5}{18}\)) - \(\dfrac{7}{5}\)
= 0 + 0 + 0 - \(\dfrac{7}{5}\)
= - \(\dfrac{7}{5}\)
Bài 1 c;
\(\dfrac{15}{14}\) - (\(\dfrac{17}{23}\) - \(\dfrac{80}{87}\) + \(\dfrac{5}{4}\)) + (\(\dfrac{17}{23}\) - \(\dfrac{15}{14}\) + \(\dfrac{1}{4}\))
= \(\dfrac{15}{14}\) - \(\dfrac{17}{23}\) + \(\dfrac{80}{87}\) - \(\dfrac{5}{4}\) + \(\dfrac{17}{23}\) - \(\dfrac{15}{14}\) + \(\dfrac{1}{4}\)
= (\(\dfrac{15}{14}-\dfrac{15}{14}\)) + (\(-\dfrac{17}{23}+\dfrac{17}{23}\)) - (\(\dfrac{5}{4}\) - \(\dfrac{1}{4}\)) + \(\dfrac{80}{87}\)
= 0 + 0 - 1 + \(\dfrac{80}{87}\)
= - \(\dfrac{7}{87}\)
Bài 1 d;
\(\dfrac{1}{25}\) - \(\dfrac{4}{27}\) + (-\(\dfrac{23}{27}\) + \(\dfrac{-1}{25}\) - \(\dfrac{5}{43}\)) + \(\dfrac{5}{43}\) - \(\dfrac{4}{7}\)
= \(\dfrac{1}{25}\) - \(\dfrac{4}{27}\) - \(\dfrac{23}{27}\) - \(\dfrac{1}{25}\) - \(\dfrac{5}{43}\) + \(\dfrac{5}{43}\) - \(\dfrac{4}{7}\)
= (\(\dfrac{1}{25}\) - \(\dfrac{1}{25}\)) - (\(\dfrac{4}{27}\) + \(\dfrac{23}{27}\)) - (\(\dfrac{5}{43}\) - \(\dfrac{5}{43}\)) - \(\dfrac{4}{7}\)
= 0 - 1 - 0 - \(\dfrac{4}{7}\)
= \(\dfrac{-11}{7}\)
A.(13 9/11 : 38/49 - 5 5/11 : 38/49): (49/38•5/11)
B.39 124/173•95 4/23 + 75 49/173•18/23-39 124/173•94 9/23
C.(7/12+1 25/31)•19 3/8 - 7 1/12 • 7 3/8
D.17/35•37 19/25 + 1 8/17 • 33 7/25 +(17/35-1 8/17)•32 6/25
Mong mọi người giúp mình các bài này.Mai phải nộp bài gấp
mình còn ko bt cơ mà mai nộp r
mik chỉ lm đc 1 câu thôi mong bn like cho
(13911:3849−5211:3849):(4938.511)={(13+911).4938−(5+211).4938}:(4938.511)=4938.(13−5+911−211):(4938.511)=4938.(8+711):(4938.511)=(8+711):511=19
7/25+(-18)/25+4/23+5/7+19/23
Tính hợp lí.🤔🤔
\(\frac{7}{25}+\frac{-18}{25}+\frac{4}{23}+\frac{5}{7}+\frac{19}{23}\)
\(=\left(\frac{7}{25}-\frac{11}{25}\right)+\left(\frac{4}{23}+\frac{19}{23}\right)+\frac{5}{7}\)
\(=\frac{-4}{25}+1+\frac{5}{7}\)
\(=\frac{-28}{175}+\frac{175}{175}+\frac{125}{175}\)
\(=\frac{272}{175}\)
\(\frac{7}{25}+\left(\frac{-18}{25}\right)+\frac{4}{23}+\frac{5}{7}+\frac{19}{23}\)
\(=\left(\frac{7-18}{25}\right)+\left(\frac{4+19}{23}\right)+\frac{5}{7}\)
\(=\frac{-11}{25}+1+\frac{5}{7}\)
\(=\frac{223}{175}\)
\(\frac{7}{25}\)\(+\)\(\frac{-18}{25}\)\(+\) \(\frac{4}{23}\)\(+\)\(\frac{5}{7}\)\(+\)\(\frac{19}{23}\)
\(=\)\(\left(\frac{7}{25}-\frac{18}{25}\right)\)\(+\)\(\left(\frac{4}{23}+\frac{19}{23}\right)\)\(+\)\(\frac{5}{7}\)
\(=\)\(\frac{-11}{25}\)\(+\)\(\frac{23}{23}\)\(+\)\(\frac{5}{7}\)
\(=\)\(\frac{-11}{25}\)\(+\)\(1\)\(+\)\(\frac{5}{7}\)
\(=\)\(\frac{14}{25}\)\(+\)\(\frac{5}{7}\)
\(=\)\(\frac{5}{2}\)
Hok tốt
1) Tính giá trị các biểu thức :
a) C = 5/18 + 8/19 - 7/21 + ( -10/36 + 11/19 + 1/3) - 5/8
b) F = 15/14 - ( 17/23 - 80/87 + 5/4 ) + ( 17/23 - 15/14 + 1/4 )
c) G = 1/25 - 4/27 + ( -23/27 + -1/25 - 5/43 ) + 5/43 - 4/7
a) Ta có:
C = 5/18 + 8/19 - 7/21 + (-10/36 + 11/19 + 1/3) - 5/8
C = 5/18 + 8/19 - 1/3 - 5/18 + 11/19 + 1/3 - 5/8
C = (5/18 - 5/18) + (8/19 + 11/19) - (1/3 - 1/3) - 5/8
C = 1 - 5/8
c = 3/8
b) F = 15/14 - (17/23 - 80/87 + 5/4) + (17/23 - 15/14 + 1/4)
F = 15/14 - 17/23 + 80/87 - 5/4 + 17/23 - 15/14 + 1/4
F = (15/14 - 15/14) - (17/23 - 17/23) + 80/87 - (5/4 - 1/4)
F = 80/87 - 1
F = -7/87
c) G = 1/25 - 4/27 + (-23/27 + -1/25 - 5/43) + 5/43 - 4/7
G = 1/25 - 4/27 - 23/27 - 1/25 - 5/43 + 5/43 - 4/7
G = (1/25 - 1/25) - (4/27 + 23/27) - (5/43 - 5/43) - 4/7
G = -1 - 4/7 = -11/7