tính nhanh: -5/7 .2/11+-5/7.9/11+5/7
8)Tính nhanh :
a) -3/7+5/13+ -4/7
b)-5/8+3/4+ -1/5+-3/8+1/4
c)6/7.8/13+6/7.9/13+ -3/13.6/7
d)-5/7.2/11+ -5/7.9/11+1 5/7
e)11 3/13 - (2 4/7+5 3/13)
f) (1-1/2)(1-1/3)(1-1/4)(1-1/5)
-5/7.2/11+-5/7.9/11+5/7
\(\dfrac{-5}{7}\cdot\dfrac{2}{11}+\dfrac{-5}{7}\cdot\dfrac{9}{11}+\dfrac{5}{7}=\dfrac{5}{7}\cdot\dfrac{-2}{11}+\dfrac{5}{7}\cdot\dfrac{-9}{11}+\dfrac{5}{7}\cdot1=\dfrac{5}{7}\cdot\left(\dfrac{-2}{11}+\dfrac{-9}{11}+1\right)=\dfrac{5}{7}\cdot0=\dfrac{0}{7}=0\)
-5/7 x (2/11 + 9/11 ) + 5/7
=-5/7 x 1 + 5/7
=0
-5/7.2/11+-5/7.9/11+5/7
\(\frac{-5}{7}.\frac{2}{11}+\frac{-5}{7}.\frac{9}{11}+\frac{5}{7}\)
\(=\frac{-5}{7}\left(\frac{2}{11}+\frac{9}{11}\right)+\frac{5}{7}\)
\(=\frac{-5}{7}.1+\frac{5}{7}\)
\(=\frac{-5}{7}+\frac{5}{7}\)
\(=0\)
-5/7 x (2/11 + 9/11 ) + 5/7
-5/7 x 1 + 5/7
0
-5/7.2/11+-5/7.9/11+1/5/7
-5/7.2/11+-5/7.9/11+1 và 5/7
ta có: \(\frac{-5}{7}.\frac{2}{11}+\frac{-5}{7}.\frac{9}{11}\)
\(=\frac{-5}{7}.\left(\frac{2}{11}+\frac{9}{11}\right)\)
\(=\frac{-5}{7}\)
\(\Rightarrow\frac{-5}{7}< \frac{5}{7}\)
\(\Rightarrow\frac{-5}{7}.\frac{2}{11}+\frac{-5}{7}.\frac{9}{11}< \frac{5}{7}\)
Học tốt nhé bn !!!
a. 5.(-2)-(-3).(-4)=
b. 1 ba phần 7- 3/14
c. -5/7.2/11+(-5)/7.9/11+1 năm phần 7
a) 5.(-2)-(-3).(-4)=(-10).(-3).(-4)
=30.(-4)
=-120
b) \(\dfrac{13}{7}-\dfrac{3}{14}=\dfrac{13}{7}+\dfrac{-3}{14}=\dfrac{26}{14}+\dfrac{-3}{14}=\dfrac{23}{14}\)
c) chả biết bạn viết cái j
Tính nhanh ; P =
2/3 -1/4 + 5/11
5/12+1-7/11
k) (-1/2)2:1/4-2.(-1/2)2
m) (-2)3.-1/24+(4/3-1 5/6):5/12
n) (6 4/9 + 7/11) - (4 4/9 - 2 4/11)
p) 10 1/5 - 5 1/2. 60/11+3:15%
q) 5/7.5/11+5/7.2/11-5/7.14/11
r) -5/7.2/11+-5/7.9/11+1 5/7
GIÚP MÌNH VỚI Ạ. CẢM ƠN MỌI NGƯỜI!
\(\left(-\dfrac{1}{2}\right)^2\div\dfrac{1}{4}-2\times\left(-\dfrac{1}{2}\right)^2\\= \dfrac{1}{4}\div\dfrac{1}{4}-2\times\dfrac{1}{4}\\ =1-\dfrac{1}{2}\\ =\dfrac{1}{2}\)
\(\left(-2\right)^3\times-\dfrac{1}{24}+\left(\dfrac{4}{3}-1\dfrac{5}{6}\right)\div\dfrac{5}{12}\)
= \(-6\times-\dfrac{1}{24}+\left(\dfrac{4}{3}-\dfrac{11}{6}\right)\div\dfrac{5}{12}\)
= \(\dfrac{1}{4}+-\dfrac{1}{2}\div\dfrac{5}{12}\)
= \(\dfrac{1}{4}+-\dfrac{6}{5}\)
= \(\dfrac{1}{4}-\dfrac{6}{5}\)
= \(-\dfrac{19}{20}\)
\(\left(6\dfrac{4}{9}+\dfrac{7}{11}\right)-\left(4\dfrac{4}{9}-2\dfrac{4}{11}\right)\\ =\dfrac{58}{9}+\dfrac{7}{11}-\dfrac{40}{9}+\dfrac{26}{11}\\ =\dfrac{58}{9}-\dfrac{40}{9}+\dfrac{7}{11}+\dfrac{26}{11}\\ =12+3\\ =15\)
\(a,\left(\dfrac{-1}{2}\right)^2:\dfrac{1}{4}-2\left(-\dfrac{1}{2}\right)^2\)
\(=\left(-\dfrac{1}{2}\right)^2\left(4-2\right)\)
\(=\dfrac{1}{4}.2=\dfrac{1}{2}\)
\(b,\left(-2\right)^3.\dfrac{-1}{24}+\left(\dfrac{4}{3}-1\dfrac{5}{6}\right):\dfrac{5}{12}\)
\(=\left(-8\right).\dfrac{-1}{24}+\left(-\dfrac{1}{2}\right).\dfrac{12}{5}\)
\(=\dfrac{1}{3}+\left(-\dfrac{1}{5}\right)=\dfrac{2}{15}\)
\(c,\left(6\dfrac{4}{9}+\dfrac{7}{11}\right)-\left(4\dfrac{4}{9}-2\dfrac{4}{11}\right)\)
\(=\dfrac{701}{99}-\dfrac{206}{99}=\dfrac{495}{99}=5\)
\(d,10\dfrac{1}{5}-5\dfrac{1}{2}.\dfrac{60}{11}+\dfrac{3}{15\%}\)
\(=\dfrac{51}{5}-30+20=\dfrac{1}{5}\)
\(e,\dfrac{5}{7}.\dfrac{5}{11}+\dfrac{5}{7}.\dfrac{2}{11}-\dfrac{5}{7}.\dfrac{14}{11}\)
\(=\dfrac{5}{7}\left(\dfrac{5}{11}+\dfrac{2}{11}-\dfrac{14}{11}\right)=\dfrac{5}{7}.\left(-\dfrac{7}{11}\right)\)
\(=-\dfrac{5}{11}\)
\(f,\dfrac{-5}{7}.\dfrac{2}{11}+\left(-\dfrac{5}{7}\right).\dfrac{9}{11}+1\dfrac{5}{7}\)
\(=\left(-\dfrac{5}{7}\right)\left(\dfrac{2}{11}+\dfrac{9}{11}\right)+\dfrac{12}{7}\)
\(=\left(-\dfrac{5}{7}\right)+\dfrac{12}{7}=1\)
\(10\dfrac{1}{5}-5\dfrac{1}{2}\times\dfrac{60}{11}+3\div15\%\\ =\dfrac{51}{5}-\dfrac{11}{2}\times\dfrac{60}{11}+3\div\dfrac{15}{100}\\ =\dfrac{51}{5}-30+20\\ =10,2-30+20\\ =0,2\)
\(\dfrac{5}{7}\times\dfrac{5}{11}+\dfrac{5}{7}\times\dfrac{2}{11}-\dfrac{5}{7}\times\dfrac{14}{11}\\ =\dfrac{5}{7}\times\left(\dfrac{5}{11}+\dfrac{2}{11}-\dfrac{14}{11}\right)\\ =\dfrac{5}{7}\times-\dfrac{7}{11}=-\dfrac{5}{11}\)
\(-\dfrac{5}{7}\times\dfrac{2}{11}+-\dfrac{5}{7}\times\dfrac{9}{11}+1\dfrac{5}{7}\\ =-\dfrac{5}{7}\times\dfrac{2}{11}+-\dfrac{5}{7}\times\dfrac{9}{11}+\dfrac{12}{7}\\ =-\dfrac{5}{7}\times\left(\dfrac{2}{11}+\dfrac{9}{11}\right)+\dfrac{12}{7}\\ =-\dfrac{5}{7}\times1+\dfrac{12}{7}\\ =1\)
tính:
a) (4-12/5).25/8-2/5:-4/25
b) (-5/24+3/4-7/12):(-5/16)
c)-5/7.2/11+-5/7.9/11
d) 6/7+5/4:(-5)-(-1/28).(-2)
a; (4 - \(\dfrac{12}{5}\)).\(\dfrac{25}{8}\) - \(\dfrac{2}{5}\) : - \(\dfrac{4}{25}\)
= 4.\(\dfrac{25}{8}\) - \(\dfrac{12}{5}\).\(\dfrac{25}{8}\) - \(\dfrac{2}{5}\) x \(\dfrac{-25}{4}\)
= \(\dfrac{25}{2}\) - \(\dfrac{15}{2}\) + \(\dfrac{5}{2}\)
= \(\dfrac{10}{2}\) + \(\dfrac{5}{2}\)
= \(\dfrac{15}{2}\)
b; (- \(\dfrac{5}{24}\) + \(\dfrac{3}{4}\) - \(\dfrac{7}{12}\)) : (- \(\dfrac{5}{16}\))
= (- \(\dfrac{5}{24}\)) : (-\(\dfrac{5}{16}\)) + \(\dfrac{3}{4}\) : (- \(\dfrac{5}{16}\)) - \(\dfrac{7}{12}\) : (- \(\dfrac{5}{16}\))
= \(\dfrac{5}{24}\) x \(\dfrac{16}{5}\) - \(\dfrac{3}{4}\) x \(\dfrac{16}{5}\) + \(\dfrac{7}{12}\) x \(\dfrac{16}{5}\)
= \(\dfrac{2}{3}\) - \(\dfrac{12}{5}\) + \(\dfrac{28}{15}\)
= \(\dfrac{10}{15}\) - \(\dfrac{36}{15}\) + \(\dfrac{28}{15}\)
= \(\dfrac{-26}{15}\) + \(\dfrac{28}{15}\)
= \(\dfrac{2}{15}\)