Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Gợi ý: Sử dụng tính chất phân phối của phép nhân đối với phép cộng để nhóm thừa số chung ra ngoài.
\(a,\dfrac{13}{14}\cdot\dfrac{-7}{8}+\dfrac{-3}{2}\)
\(=-\dfrac{13}{16}+\dfrac{-3}{2}\)
\(=-\dfrac{13}{16}+\dfrac{-24}{16}\)
\(=-\dfrac{37}{16}\)
\(b,\dfrac{5}{17}+\dfrac{-15}{34}\cdot\dfrac{2}{5}\)
\(=\dfrac{5}{17}+\dfrac{-3}{17}\)
\(=\dfrac{2}{17}\)
\(c,\dfrac{1}{5}:\dfrac{1}{10}-\dfrac{1}{3}\cdot\left(\dfrac{6}{5}-\dfrac{2}{4}\right)\)
\(=2-\dfrac{1}{3}\cdot\dfrac{7}{10}\)
\(=2-\dfrac{7}{30}\)
\(=\dfrac{53}{30}\)
\(d,\dfrac{-3}{4}:\left(\dfrac{12}{-5}-\dfrac{-7}{10}\right)\)
\(=\dfrac{-3}{4}:\dfrac{-17}{10}\)
\(=\dfrac{15}{34}\)
Bài 1:
\(a,=\frac{2}{3}-\frac{16}{3}=\frac{-14}{3}\)
\(b,=\left(\frac{3}{7}+\frac{4}{7}\right)+\left(-\frac{6}{19}+\frac{-13}{19}\right)=1-1=0\)
\(c,=\frac{3}{5}.\left(\frac{8}{9}-\frac{7}{9}+\frac{26}{9}\right)=\frac{3}{5}.3=\frac{9}{5}\)
a,\(\dfrac{1}{2}\).\(\dfrac{4}{3}\)-\(\dfrac{20}{3}\).\(\dfrac{4}{5}\)=\(\dfrac{2}{3}\)-\(\dfrac{16}{3}\)=-\(\dfrac{14}{3}\)
c,
= \(\dfrac{5}{9}.\left(\dfrac{7}{13}+\dfrac{9}{13}+\dfrac{-3}{13}\right)\)
= \(\dfrac{5}{9}.1\)
= \(\dfrac{5}{9}\)
1: \(\dfrac{1}{2}+\dfrac{9}{10}+\dfrac{5}{6}-\dfrac{11}{14}-\dfrac{1}{3}+\dfrac{-4}{35}\)
\(=\left(\dfrac{1}{2}+\dfrac{5}{6}-\dfrac{1}{3}\right)+\dfrac{9}{10}-\left(\dfrac{11}{14}+\dfrac{4}{35}\right)\)
\(=\dfrac{3+5-2}{6}+\dfrac{9}{10}-\dfrac{55+8}{70}\)
\(=1+\dfrac{9}{10}-\dfrac{9}{10}\)
=1
a. \(\left(\dfrac{-2}{7}+\dfrac{4}{7}\right)+\dfrac{1}{7}=\dfrac{2}{7}+\dfrac{1}{7}=\dfrac{3}{7}\)
b. \(\left(\dfrac{-8}{19}+\dfrac{27}{19}\right)+\left(\dfrac{-4}{21}+\dfrac{-17}{21}\right)+\dfrac{-12}{16}=\dfrac{19}{19}+\dfrac{-21}{21}+\dfrac{-12}{16}\)
\(=1+\left(-1\right)+\dfrac{-12}{16}=\dfrac{-12}{16}\)
c. \(\dfrac{-3}{7}+\dfrac{-11}{13}+\dfrac{-2}{13}+\dfrac{3}{7}+1=\left(\dfrac{-3}{7}+\dfrac{3}{7}\right)+\left(\dfrac{-11}{13}+\dfrac{-2}{13}\right)+1=0-1+1=0\)
-2/7 + 2/7 : 3/5
= -2/7 + 2/7. 3/5
= -2/7 + 35/6
= -12/42 + 245/42
= -233/42
−819+−421−1721+271919−8+21−4−2117+1927
= (-4/21 - 17/21) + (-8/19 + 27/19)
= - 13/21 + -19/19
= (-13/21)+ (-1)
= (-13/21) + (-1/1)
= (-13/21) + (-13/21)
= - 26/21
65.313−65.161356.133−56.1316
=6/5. (3/13 - 16/13)
= 6/5. (-13/13)
=6/5. (-1)
=6/5. (-1/1)
=6/5. (-6/5)
=(-36/25)
a: \(A=\dfrac{7}{12}+\dfrac{5}{72}-\dfrac{11}{36}=\dfrac{42}{72}+\dfrac{5}{72}-\dfrac{22}{72}=\dfrac{25}{72}\)
b: \(B=\dfrac{8+5}{10}:\dfrac{-5}{13}=\dfrac{13}{10}\cdot\dfrac{13}{-5}=-\dfrac{169}{100}\)
c: \(C=\left(\dfrac{88}{132}-\dfrac{33}{132}+\dfrac{60}{132}\right):\left(\dfrac{55}{132}+\dfrac{132}{132}-\dfrac{84}{132}\right)\)
\(=\dfrac{88-33+60}{55+132-84}=\dfrac{115}{103}\)
a, \(=\dfrac{2}{9}-\dfrac{10}{10}=\dfrac{2}{9}-1=-\dfrac{7}{9}\)
b, \(=-\dfrac{12}{6}+\dfrac{2}{5}=-2+\dfrac{2}{5}=-\dfrac{8}{5}\)
c, \(=\dfrac{27}{13}-1=\dfrac{14}{13}\)
d, \(=\dfrac{12}{11}+\dfrac{7}{19}+\dfrac{12}{19}=\dfrac{12}{11}+1=\dfrac{23}{11}\)
a, \(4\times\left(-\dfrac{1}{2}\right)^3-2\times\left(-\dfrac{1}{2}\right)^2+3\times\left(-\dfrac{1}{2}\right)+1\)
\(=\left(-\dfrac{1}{2}\right)\left[\left(4\times-\dfrac{1}{2}\right)-\left(2\times-\dfrac{1}{2}\right)+3\right]+1\)
\(=\left(-\dfrac{1}{2}\right)\left(-2+1+3\right)+1\)
\(=\left(-\dfrac{1}{2}\right)2+1\)
\(=-1+1\)
\(=0\)
@Trịnh Thị Thảo Nhi
a, 4×(−12)3−2×(−12)2+3×(−12)+14×(−12)3−2×(−12)2+3×(−12)+1
=(−12)[(4×−12)−(2×−12)+3]+1=(−12)[(4×−12)−(2×−12)+3]+1
=(−12)(−2+1+3)+1=(−12)(−2+1+3)+1
=(−12)2+1=(−12)2+1
=−1+1=−1+1
=0=0
a) \(\frac{1}{3}+\frac{3}{4}-\frac{5}{6}\)
\(=\frac{1}{3}+\frac{3}{4}+\frac{-5}{6}\)
\(=\frac{1.4+3.3+\left(-5\right).2}{12}\)
\(=\frac{4+9+\left(-10\right)}{12}\)
\(=\frac{3}{12}\)
\(=\frac{1}{4}\)
b) \(\frac{-2}{3}+\frac{6}{5}\div\frac{2}{3}-\frac{2}{15}\text{ }\)
\(=\frac{-2}{3}+\frac{6}{5}\times\frac{3}{2}-\frac{2}{15}\)
\(=\frac{-2}{3}+\frac{18}{10}-\frac{2}{15}\)
\(=\frac{-2}{3}+\frac{9}{5}+\frac{-2}{15}\)
\(=\frac{\left(-2\right).5+9.3+\left(-2\right)}{15}\)
\(=\frac{\left(-10\right)+27+\left(-2\right)}{15}\)
\(=\frac{15}{15}\)
\(=1\)
c) \(\frac{-3}{7}+\frac{5}{13}+\frac{-4}{7}\text{ }\)
\(=\left(\frac{-3}{7}+\frac{-4}{7}\right)+\frac{5}{13}\)
\(=\frac{-7}{7}+\frac{5}{13}\)
\(=-1+\frac{5}{13}\)
\(=\frac{-13}{13}+\frac{5}{13}\)
\(=\frac{-8}{13}\)
d) \(\frac{12}{19}+\frac{-8}{13}-\frac{12}{19}+\frac{5}{-13}+2\text{ }\)
\(=\frac{12}{19}+\frac{-8}{13}+\frac{-12}{19}+\frac{-5}{13}+2\)
\(=\left(\frac{12}{19}+\frac{-12}{19}\right)+\left(\frac{-8}{13}+\frac{-5}{13}\right)+2\)
\(=0+\frac{-13}{13}+2\)
\(=0+\left(-1\right)+2\)
\(=-1\)
a) \dfrac{1}{3}+\dfrac{3}{4}-\dfrac{5}{6}31+43−65
=\dfrac{4}{12}+\dfrac{9}{12}-\dfrac{10}{12}=124+129−1210
=\dfrac{4+9-10}{12}=124+9−10
=\dfrac{3}{12}=123
=\dfrac{1}{4}=41.
b) \dfrac{-2}{3}+\dfrac{6}{5}:\dfrac{2}{3}-\dfrac{2}{15}3−2+56:32−152
=\dfrac{-2}{3}+\dfrac{6}{5}.\dfrac{3}{2}-\dfrac{2}{15}=3−2+56.23−
a) \dfrac{1}{3}+\dfrac{3}{4}-\dfrac{5}{6}31+43−65
=\dfrac{4}{12}+\dfrac{9}{12}-\dfrac{10}{12}=124+129−1210
=\dfrac{4+9-10}{12}=124+9−10
=\dfrac{3}{12}=123
=\dfrac{1}{4}=41.
b) \dfrac{-2}{3}+\dfrac{6}{5}:\dfrac{2}{3}-\dfrac{2}{15}3−2+56:32−152
=\dfrac{-2}{3}+\dfrac{6}{5}.\dfrac{3}{2}-\dfrac{2}{15}=3−2+56.23−152
=\dfrac{-2}{3}+\dfrac{18}{10}-\dfrac{2}{15}=3−2+1018−152
=\dfrac{-2}{3}+\dfrac{9}{5}-\dfrac{2}{15}=3−2+59−152
=\dfrac{-10}{15}+\dfrac{27}{15}-\dfrac{2}{15}=15−10+1527−152
=\dfrac{1}{3}=31.
c) \dfrac{-3}{7}+\dfrac{5}{13}+\dfrac{-4}{7}7−3+135+7−4
=\left( \dfrac{-3}{7}+\dfrac{-4}{7} \right)+\dfrac{5}{13}=(7−3+7−4)+135
=\dfrac{-7}{7}+\dfrac{5}{13}=7−7+135
=-1+\dfrac{5}{13}=−1+135
=\dfrac{-8}{13}=13−8.
d) \dfrac{12}{19}+\dfrac{-8}{13}-\dfrac{12}{19}+\dfrac{5}{-13}+21912+13−8−1912+−135+2
=\dfrac{12}{19}+\dfrac{-8}{13}-\dfrac{12}{19}+\dfrac{-5}{13}+2=1912+13−8−1912+13−5+2
=\left( \dfrac{12}{19}-\dfrac{12}{19} \right)+\left( \dfrac{-8}{13}+\dfrac{-5}{13} \right)+2=(1912−1912)+(13−8+13−5)+2
=0+\dfrac{-13}{13}+2=0+13−13+2
=1=1.
1
a, 1/3 + 3/4 - 5/6
=4/12 + 9/12 - 10/12
=4 + 9 - 10/ 2
=3/12 = 1/4
b, -2/3 + 6/5 : 2/3 - 2/15
=-2/3 + 6/5 . 3/2 - 2/15
=-2/3 + 18/10 - 2/15
=-2/3 + 9/5 - 2/15
=-10/15 + 27/15 - 2/15
=1/3
c,-3/7 + 5/13 + -4/7
= (-3/7 + -4/7) + 5/13
= -7/7 + 5/13
=-1 + 5/13 = -3/13
d,12/19 + -8/13 - 12/19 + 5/-13 + 2
= 12/19 + -8/13 - 12/19 + -5/13 + 2
=(12/19 - 12/19) + (-8/13 + -5/13) + 2
=0 + -13/13 + 2
=1
1/3+3/4-5/6
=13/2-5/6
=1/4
-2/3+6/5:2/3-2/15
=-2/3+6/5.3/2-2/15
=-2/3+18/10-2/15
=-2/3+9/5-2/15
=-10/15+27/15-2/15
=1/3
-3/7+5/13+(-4/7)
=[-3/7+(-4/7)]+5/13
=-7/7+5/13
=(-1)+5/13
=-8/13
12/19+(-8/13)-12/19+(-5/13)+2
=[12/19 -12/19]+[-8/13+(-5/13)]
=0+(-13/13)+2
=1
=1/3 +3/4 -5/6
=13/12 - 5/6
=1/4
-2/3 +5/6 :2/3 -2/15
=1/6+5/6:2/3-2/15
=1:2/3-2/15
=3/2-2/15
=1/5
-3/7+5/13+-5/7
=7/8+-5/7
=5/7
=0+\dfrac{-13}{13}+2
=1
a\(\dfrac{1}{3}+\dfrac{3}{4}-\dfrac{5}{6}\)
=\(\dfrac{4}{12}+\dfrac{9}{12}-\dfrac{10}{12}\)
=\(\dfrac{1}{4}\)
=\(\dfrac{-2}{3}+\dfrac{6}{5}:\dfrac{2}{3}-\dfrac{2}{15}\)
=\(\dfrac{-2}{3}+\dfrac{6}{5}.\dfrac{3}{2}-\dfrac{2}{15}\)
=\(\dfrac{-2}{3}+\dfrac{9}{5}-\dfrac{2}{15}\)
=\(\dfrac{-10}{15}-\dfrac{27}{15}-\dfrac{2}{15}\)
=\(\dfrac{1}{3}\)
c\(\dfrac{-3}{7}+\dfrac{5}{13}+\dfrac{-4}{7}\)
=(\(\dfrac{-3}{7}+\dfrac{-4}{7}\))+\(\dfrac{5}{13}\)
= -1+\(\dfrac{5}{13}\)
=\(\dfrac{-13}{13}+\dfrac{5}{13}\)
=\(\dfrac{-8}{13}\)
d\(\dfrac{12}{19}+\dfrac{-8}{13}-\dfrac{12}{19}+\dfrac{5}{-13}+2\)
=(\(\dfrac{12}{19}-\dfrac{12}{19})+(\dfrac{-8}{13}+\dfrac{-5}{13})+2\)
=0+(-1)+2
=1
a)\(\dfrac{1}{3}+\dfrac{3}{4}-\dfrac{5}{6}=\dfrac{4}{12}+\dfrac{9}{12}-\dfrac{10}{12}=\dfrac{4+9-10}{12}=\dfrac{3}{12}=\dfrac{1}{4}\)
b)\(\dfrac{-2}{3}+\dfrac{6}{5}:\dfrac{2}{3}-\dfrac{2}{15}=\dfrac{-2}{3}+\dfrac{6}{5}.\dfrac{3}{2}-\dfrac{2}{15}=\dfrac{-2}{3}+\dfrac{18}{10}-\dfrac{2}{15}=\dfrac{-10}{15}+\dfrac{27}{15}-\dfrac{2}{15}=\dfrac{1}{3}\)
c)\(\dfrac{-3}{7}+\dfrac{5}{13}+\dfrac{-4}{7}=\dfrac{-3}{7}+\dfrac{-4}{7}+\dfrac{5}{13}=\dfrac{-7}{7}+\dfrac{5}{13}=-1+\dfrac{5}{13}=\dfrac{-8}{13}\)
d)\(\dfrac{12}{19}+\dfrac{-8}{13}-\dfrac{12}{19}+\dfrac{5}{-13}+2=\dfrac{12}{19}+\dfrac{-8}{13}-\dfrac{12}{19}+\dfrac{-5}{13}+2=\dfrac{12}{19}-\dfrac{12}{19}+\dfrac{-8}{13}+\dfrac{-5}{13}+2=0+\dfrac{-13}{13}+2=1\)
dhhdfdgfdgf
a) \dfrac{1}{3}+\dfrac{3}{4}-\dfrac{5}{6}31+43−65
=\dfrac{4}{12}+\dfrac{9}{12}-\dfrac{10}{12}=124+129−1210
=\dfrac{4+9-10}{12}=124+9−10
=\dfrac{3}{12}=123
=\dfrac{1}{4}=41.
b) \dfrac{-2}{3}+\dfrac{6}{5}:\dfrac{2}{3}-\dfrac{2}{15}3−2+56:32−152
=\dfrac{-2}{3}+\dfrac{6}{5}.\dfrac{3}{2}-\dfrac{2}{15}=3−2+56.23−
A,1/4
B,6/15
C,8/13
D,2
A,1/4
B,1
C,-8/13
D,-1
A,1/4
B,1
C,-8/13
D,-1