a) 4/5 + 6/5 : 7/15 - 3/7
b) 9/13 . 5/3 + −6/13 .9/13 - 9/13 . 20/13
Đề: thực hiện phép tính
Giúp mk nhé mk cần gấp lắm
thực hiện phép tính :
a, A=1-3-5-7-9-11-13-15-...-97-99
b,B=1+3-5-7+9+11-13-15+...-97-99
c,C=1-3-5+7+9-11-13+15+...+97-99
d,D=-(5)-(2-7)-(5-12)-(4-6)-(-3)
mk đang cần gấp giúp mk vs nha cảm ơn nhìu
a,
A=1−3−5−7−9−...−97−99a)A=1−3−5−7−9−...−97−99
=1−(3+5+7+...+99)=1−(3+5+7+...+99)
=1−(99+3).[(99−3):2+1]2=1−(99+3).[(99−3):2+1]2
=1−2499=−2498=1−2499=−2498
b)B=1+3−5−7+9+...+97−99b)B=1+3−5−7+9+...+97−99
=(−8)+(−8)+(−8)+...+(−8)+97−99=(−8)+(−8)+(−8)+...+(−8)+97−99
=(−8).12+(−2)=−98=(−8).12+(−2)=−98
c)C=1−3−5+7+9−11−13+15+...+97−99c)C=1−3−5+7+9−11−13+15+...+97−99
=0+0+0+0+0+...+0−99=0+0+0+0+0+...+0−99
=−99
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 = \(\dfrac{\left(-2\right)^3}{5}\)
Sắp xếp các phân số sau theo thứ tự từ lớn đến bé
a) 6/15, 6/17, 6/21, 6/7
b) 7/9, 3/5, 1/3, 9/11, 11/13
c) 7/4, 10/7, 15/12, 13/10, 20/17, 5/2
nhanh nha, mk đang cần gấp
Câu 1 : thực hiện phép tính
A = 13/6 + 5/8 : -3/4 - 7/12 . 4
B = ( 7 3/5 - 2 1/3 ) + ( 4/3 - 4 3/5 )
C = 7/5 . 4/9 + 7/5 : 9/16 - 14/10 . 2/9
Ai giúp mình với, làm đầy đủ 3 câu nhé. Pleasee mình cần gấp lắm sẽ tick nhé
a, 13/6+5/8 : -3/4 - 7/12.4
= 13/6 + -5/6-7/3
=8/6-7/3
= -6/6
= -1
b, ( 73/5 - 21/3) + ( 4/3-43/5 )
= 73/5-21/3+4/3-43/5
=( 73/5-43/5)-(21/3-4/3)
= 6-17/3
=1/3
c, 7/5.4/9 +7/5: 9/16- 14/10.2/9
= 7/5.4/9 +7/5.16/9 - 14/45
=7/5.(4/9+16/9)-14/45
=7/5.20/9-14/45
= 140/45 - 14/45
= 126/45
Xong rùi nè! Nhưng bạn kiểm tra lại giùm nhé vì làm vào ban đêm nên hơi bất tiện
a: =35/17-18/17-9/5+4/5
=1-1=0
b: =-7/19(3/17+8/11-1)
=7/19*18/187=126/3553
c: =26/15-11/15-17/3-6/13
=1-6/13-17/3
=7/13-17/3=-200/39
a) 5/9*10/11+5/9*14/11-5/9*15/11 b) 6/7*8/13+6/13*9/7-3/13*6/7 Giúp mk vs ạ
a, \(\dfrac{5}{9}.\dfrac{10}{11}+\dfrac{5}{9}.\dfrac{14}{11}-\dfrac{5}{9}.\dfrac{15}{11}=\dfrac{5}{9}.\left(\dfrac{10}{11}+\dfrac{14}{11}-\dfrac{15}{11}\right)=\dfrac{5}{9}.\dfrac{9}{11}=\dfrac{5}{11}\)
b, \(\dfrac{6}{7}.\dfrac{8}{13}+\dfrac{6}{13}.\dfrac{9}{7}-\dfrac{3}{13}.\dfrac{6}{7}\)\(=\dfrac{6}{7}.\left(\dfrac{8}{13}-\dfrac{3}{13}\right)+\dfrac{6}{13}.\dfrac{9}{7}=\dfrac{6}{7}.\dfrac{5}{13}+\dfrac{54}{91}=\dfrac{30}{91}+\dfrac{54}{91}=\dfrac{84}{91}=\dfrac{12}{13}\)
Bạn ơi, gõ latex cho dễ nhìn nhé!
Tính
a, -(-5)-(+7)+(+3)+(-8)
b, -(-15)-|-10|+|-9|-|5|
c, 14-(-13)-(17)+(-12)
d, -|-14| + |-10| - (-12) + (-8)
e, -(-11) + (-15) + (13) - 21
Bài 2 tìm x
1, -x + 20 = - (-15) - (8) + 13
2, -(-10) + x = -13 + (-9) + (-6)
3, 8-(-12) + 10 = - (-14) - x
4. - (+12) + (-x) - (-3) = 5 - (-7)
5. 14 - x + (-10) = - (-9) + (+15)
6. 12 - (-17) + (-3) = -5 + x
7. X - (-19) - (+32) = 14 - (+16)
8. X - |-15| - |7| = - (-9) + |-5|
9. 15 - x + 17 = 13 - (-21)
10. - |-5| - (-x) +4 = 3 - (-25)
Mọi NGƯỜI GIẢI GIÚP MÌNH VỚI MK CẦN GẤP, MỌI NGƯỜI GHI RÕ CÁCH LÀM RA NHÉ! CẢM ƠN MỌI NGƯỜI
Bạn ơi bạn làm đc bao nhiêu thì làm phụ mình nhé
bài1
a,
5 - 7 + 3 +(-8)
= -2 + 3 + ( - 8)
= 1 + (-8)= -7
a; - (-5) - (+7) + (+3) + (-8)
= 5 - 7 + 3 - 8
= (5 + 3 - 8) - 7
= (8 - 8) - 7
= 0 - 7
= - 7
Thực hiện phép tính:
1,-4/7 + 2/3x -9/14
2,17/13 - ( 4/13 - 11 )
3, 8 2/7 - ( 3 4/9 + 4 2/7 )
5, ( 2/3 - 1 1/2): 4/3 + 1/2
6, -5/13 + 2/5 + -8/13 + 3/5 - 3/7
7, 6/5 x 3/7 + 6/5 : 7/10 + 6/5
\(1,-\dfrac{4}{7}+\dfrac{2}{3}\times\dfrac{-9}{14}\)
\(=\dfrac{-4}{7}+\dfrac{-18}{42}\)
\(=\dfrac{-4\times6}{7\times6}+\dfrac{-18}{42}\)
\(=\dfrac{-20}{42}+\dfrac{-18}{42}\)
\(=-\dfrac{38}{42}\)
\(=-\dfrac{19}{21}\)
\(2,\dfrac{17}{13}-\left(\dfrac{4}{13}-11\right)\)
\(=\dfrac{17}{13}-\dfrac{4}{13}+11\)
\(=\dfrac{13}{13}+11\)
\(=1+11\)
\(=12\)
\(3,8\dfrac{2}{7}-\left(3\dfrac{4}{9}+4\dfrac{2}{7}\right)\)
\(=\dfrac{58}{7}-\left(\dfrac{31}{9}+\dfrac{30}{7}\right)\)
\(=\dfrac{58}{7}-\dfrac{31}{9}-\dfrac{30}{7}\)
\(=\dfrac{58}{7}-\dfrac{30}{7}-\dfrac{31}{9}\)
\(=\dfrac{28}{7}-\dfrac{31}{9}\)
\(=\dfrac{28\times9}{7\times9}-\dfrac{31\times7}{9\times7}\)
\(=\dfrac{252}{63}-\dfrac{217}{63}\)
\(=\dfrac{35}{63}\)
\(=\dfrac{5}{9}\)
\(5,\left(\dfrac{2}{3}-1\dfrac{1}{2}\right):\dfrac{4}{3}+\dfrac{1}{2}\)
\(=\left(\dfrac{2}{3}-\dfrac{3}{2}\right):\dfrac{4}{3}+\dfrac{1}{2}\)
\(=\left(\dfrac{2\times2}{3\times2}-\dfrac{3\times3}{2\times3}\right):\dfrac{4}{3}+\dfrac{1}{2}\)
\(=\left(\dfrac{4}{6}-\dfrac{9}{6}\right):\dfrac{4}{3}+\dfrac{1}{2}\)
\(=\dfrac{-5}{6}:\dfrac{4}{3}+\dfrac{1}{2}\)
\(=\dfrac{-5}{6}\times\dfrac{3}{4}+\dfrac{1}{2}\)
\(=\dfrac{-15}{24}+\dfrac{1}{2}\)
\(=\dfrac{-15}{24}+\dfrac{1\times12}{2\times12}\)
\(=\dfrac{-15}{24}+\dfrac{12}{24}\)
\(=\dfrac{-3}{24}\)
\(=-\dfrac{1}{8}\)
\(6,\dfrac{-5}{13}+\dfrac{2}{5}+\dfrac{-8}{13}+\dfrac{3}{5}-\dfrac{3}{7}\)
\(=\left(\dfrac{-5}{13}+\dfrac{-8}{13}\right)+\left(\dfrac{2}{5}+\dfrac{3}{5}\right)-\dfrac{3}{7}\)
\(=\dfrac{-13}{13}+\dfrac{5}{5}-\dfrac{3}{7}\)
\(=-1+1-\dfrac{3}{7}\)
\(=-\dfrac{3}{7}\)
\(7,\dfrac{6}{5}\times\dfrac{3}{7}+\dfrac{6}{5}:\dfrac{7}{10}+\dfrac{6}{5}\)
\(=\dfrac{6}{5}\times\dfrac{3}{7}+\dfrac{6}{5}\times\dfrac{10}{7}+\dfrac{6}{5}\)
\(=\dfrac{6}{5}\times\left(\dfrac{3}{7}+\dfrac{10}{7}+1\right)\)
\(=\dfrac{6}{5}\times\left(\dfrac{3}{7}+\dfrac{10}{7}+\dfrac{1\times7}{1\times7}\right)\)
\(=\dfrac{6}{5}\times\left(\dfrac{3}{7}+\dfrac{10}{7}+\dfrac{7}{7}\right)\)
\(=\dfrac{6}{5}\times\dfrac{20}{7}\)
\(=\dfrac{120}{35}\)
\(=\dfrac{24}{7}\)
Thực hiện phép tính (Tính hợp lý nếu có thể)
a) -10/13 + 5/17 – 3/13 + 12/17 – 11/20
b) 3/4 + -5/6 – 11/-12
c) [13. 4/9 + 2. 1/9] – 3. 4/9
d) 1,25 : 15/20 + [25% – 5/6] : 4. 2/3
Tìm x, biết
a)x – 1/3 = 5/14 . -7/6
b) 3/4 + 1/4 x = 0,2
c) 1/12 .x2 = 1. 1/3
a; - \(\dfrac{10}{13}\) + \(\dfrac{5}{17}\) - \(\dfrac{3}{13}\) + \(\dfrac{12}{17}\) - \(\dfrac{11}{20}\)
= - (\(\dfrac{10}{13}\) + \(\dfrac{3}{13}\)) + (\(\dfrac{5}{17}\) + \(\dfrac{12}{17}\)) - \(\dfrac{11}{20}\)
= - 1 + 1 - \(\dfrac{11}{20}\)
= 0 - \(\dfrac{11}{20}\)
= - \(\dfrac{11}{20}\)
b; \(\dfrac{3}{4}\) + \(\dfrac{-5}{6}\) - \(\dfrac{11}{-12}\)
= \(\dfrac{9}{12}\) - \(\dfrac{10}{12}\) + \(\dfrac{11}{12}\)
= \(\dfrac{10}{12}\)
= \(\dfrac{5}{6}\)
c; [13.\(\dfrac{4}{9}\) + 2.\(\dfrac{1}{9}\)] - 3.\(\dfrac{4}{9}\)
= [\(\dfrac{52}{9}\) + \(\dfrac{2}{9}\)] - \(\dfrac{4}{3}\)
= \(\dfrac{54}{9}\) - \(\dfrac{4}{3}\)
= \(\dfrac{14}{3}\)
d; 1,25 : \(\dfrac{15}{20}\) + [25% - \(\dfrac{5}{6}\)] : 4.\(\dfrac{2}{3}\)
= 1,25 x \(\dfrac{20}{15}\) + [\(\dfrac{1}{4}\) - \(\dfrac{5}{6}\)] : 4.\(\dfrac{2}{3}\)
= \(\dfrac{5}{3}\) - \(\dfrac{7}{12}\) : 4 x \(\dfrac{2}{3}\)
= \(\dfrac{5}{3}\) - \(\dfrac{7}{48}\).\(\dfrac{2}{3}\)
= \(\dfrac{5}{3}\) - \(\dfrac{7}{72}\)
= \(\dfrac{113}{72}\)