đề bài:tính giá trị của biểu thức
a| (3 - 0,6) - (7 + bamộtphầnbốn - 8/5) - (9 - haimộtphầnbốn)
b| (-5/8 + 7/6 - 0/8) - (5/6 - 7/8 - 1,4) + (3/4 + 5/3 + 12/5)
Tính giá trị biểu thức:
a) ( − 9 ) . ( − 5 ) + ( − 7 ) . 12.
b) ( − 4 ) . 12 + ( − 3 ) . ( − 8 )
c) ( − 12 ) . 7 − 6 . ( − 5 ) .
d) ( − 6 ) . 9 − ( − 9 ) . 8.
Tính giá trị của biểu thức : 1*2*3+2*3*4+3*4*5+4*5*6+5*6*7+6*7*8+7*8*9+8*9*10
Tính giá trị của biểu thức( ghi rõ ràng)
a) 6/11 + 6 + 5/7 =.....
B) 9/8 X 3/12 : 5/9=....
c) 8/7 : 4 + 2 =......
D) 3/5 + 4 : 6/4=....
Giúp mik với ah
LM XONG TRONG TỐI HÔM 26/3/2023 NHÉ MN!
\(a,\dfrac{6}{11}+6+\dfrac{5}{7}=\dfrac{42+462+55}{77}=\dfrac{559}{77}\)
\(b,\dfrac{9}{8}\times\dfrac{3}{12}:\dfrac{5}{9}=\dfrac{9}{8}\times\dfrac{3}{12}\times\dfrac{9}{5}=\dfrac{243}{480}=\dfrac{81}{160}\)
\(c,\dfrac{8}{7}:4+2=\dfrac{8}{7}\times\dfrac{1}{4}+2=\dfrac{8}{28}+2=\dfrac{2}{7}+2=\dfrac{16}{7}\)
\(d,\dfrac{3}{5}+4:\dfrac{6}{4}=\dfrac{3}{5}+4\times\dfrac{4}{6}=\dfrac{3}{5}+\dfrac{8}{3}=\dfrac{49}{15}\)
\(a,\dfrac{6}{11}+6+\dfrac{5}{7}=\dfrac{6}{11}+\dfrac{66}{11}+\dfrac{5}{7}=\dfrac{72}{11}+\dfrac{5}{7}=\dfrac{504}{77}+\dfrac{55}{77}=\dfrac{559}{77}\)
\(b,\dfrac{9}{8}\times\dfrac{3}{12}:\dfrac{5}{9}=\dfrac{9}{32}:\dfrac{5}{9}=\dfrac{9}{32}\times\dfrac{9}{5}=\dfrac{81}{160}\)
\(c,\dfrac{8}{7}:4+2=\dfrac{8}{7}\times\dfrac{1}{4}+2=\dfrac{2}{7}+2=\dfrac{2}{7}+\dfrac{14}{7}=\dfrac{16}{7}\)
\(d,\dfrac{3}{5}+4:\dfrac{6}{4}=\dfrac{3}{5}+4\times\dfrac{4}{6}=\dfrac{3}{5}+\dfrac{8}{3}=\dfrac{9}{15}+\dfrac{40}{15}=\dfrac{49}{15}\)
bài 5: tính giá trị biểu thức sau một cách hợp lí
A = -7/21 + ( 1+1/3) B=2/15 +(5/9+ -6/9)
C=9-1/5 + 3/12 ) + -3/4
bài 6
a) x + 7/8 = 13/12 b) - (-6)/12 - x = 9/48
c) x+ 4/6 = 5/25 - (-7)/15 c) x + 4/5 = 6/20 - (-7)/3
`5`
`a, -7/21 +(1+1/3)`
`=-7/21 + ( 3/3 + 1/3)`
`=-7/21+ 4/3`
`=-7/21+ 28/21`
`= 21/21`
`=1`
`b, 2/15 + ( 5/9 + (-6)/9)`
`= 2/15 + (-1/9)`
`= 1/45`
`c, (9-1/5+3/12) +(-3/4)`
`= ( 45/5-1/5 + 3/12)+(-3/4)`
`= ( 44/5 + 3/12)+(-3/4)`
`= 9,05 +(-0,75)`
`=8,3`
`6`
`x+7/8 =13/12`
`=>x= 13/12 -7/8`
`=>x=5/24`
`-------`
`-(-6)/12 -x=9/48`
`=> 6/12 -x=9/48`
`=>x= 6/12-9/48`
`=>x=5/16`
`---------`
`x+4/6 =5/25 -(-7)/15`
`=>x+4/6 =1/5 + 7/15`
`=> x+ 4/6=10/15`
`=>x=10/15 -4/6`
`=>x=0`
`----------`
`x+4/5 = 6/20 -(-7)/3`
`=>x+4/5 = 6/20 +7/3`
`=>x+4/5 = 79/30`
`=>x=79/30 -4/5`
`=>x= 79/30-24/30`
`=>x= 55/30`
`=>x= 11/6`
\(5)\)
\(A=\dfrac{-7}{21}+\left(1+\dfrac{1}{3}\right)\)
\(A=\dfrac{-7}{21}+\dfrac{4}{3}\)
\(A=\dfrac{-7}{21}+\dfrac{28}{21}\)
\(A=1\)
\(--------------\)
\(B=\dfrac{2}{15}+\left(\dfrac{5}{9}+\dfrac{-6}{9}\right)\)
\(B=\dfrac{2}{15}+\dfrac{-1}{9}\)
\(B=\dfrac{18}{135}+\dfrac{-15}{135}\)
\(B=\dfrac{1}{45}\)
\(------------\)
\(C=9-\dfrac{1}{5}+\dfrac{3}{12}+\dfrac{-3}{4}\)
\(C=\dfrac{44}{5}+\dfrac{3}{12}+\dfrac{-3}{4}\)
\(C=\dfrac{528}{60}+\dfrac{15}{60}+\dfrac{-3}{4}\)
\(C=\dfrac{181}{20}+\dfrac{-3}{4}\)
\(C=\dfrac{181}{20}+\dfrac{-15}{20}\)
\(C=\dfrac{83}{10}\)
\(6)\)
\(a)\) \(x+\dfrac{7}{8}=\dfrac{13}{12}\)
\(x=\dfrac{13}{12}-\dfrac{7}{8}\)
\(x=\dfrac{104}{96}-\dfrac{84}{96}\)
\(x=\dfrac{5}{24}\)
\(b)\) \(\dfrac{-6}{12}-x=\dfrac{9}{48}\)
\(\dfrac{-1}{2}-x=\dfrac{3}{16}\)
\(x=\dfrac{-1}{2}-\dfrac{3}{16}\)
\(x=\dfrac{-8}{16}-\dfrac{3}{16}\)
\(x=\dfrac{-11}{16}\)
\(c)\) \(x+\dfrac{4}{6}=\dfrac{5}{25}-\left(-\dfrac{7}{15}\right)\)
\(x+\dfrac{4}{6}=\dfrac{5}{25}+\dfrac{7}{15}\)
\(x+\dfrac{4}{6}=\dfrac{75}{375}+\dfrac{105}{375}\)
\(x+\dfrac{4}{6}=\dfrac{12}{25}\)
\(x=\dfrac{12}{25}-\dfrac{4}{6}\)
\(x=\dfrac{72}{150}-\dfrac{100}{150}\)
\(x=\dfrac{-14}{75}\)
\(d)\) \(x+\dfrac{4}{5}=\dfrac{6}{20}-\left(-\dfrac{7}{3}\right)\)
\(x+\dfrac{4}{5}=\dfrac{6}{20}+\dfrac{7}{3}\)
\(x+\dfrac{4}{5}=\dfrac{18}{60}+\dfrac{140}{60}\)
\(x+\dfrac{4}{5}=\dfrac{79}{30}\)
\(x=\dfrac{79}{30}-\dfrac{4}{5}\)
\(x=\dfrac{79}{30}-\dfrac{24}{30}\)
\(x=\dfrac{11}{6}\)
Giải:
\(A=\dfrac{-7}{21}+\left(1+\dfrac{1}{3}\right)\)
\(A=\dfrac{-7}{21}+\dfrac{4}{3}\)
\(A=\dfrac{-7}{21}+\dfrac{28}{21}\)
\(A=\dfrac{21}{21}=1\)
\(B=\dfrac{2}{15}+\left(\dfrac{5}{9}+\dfrac{-6}{9}\right)\)
\(B=\dfrac{2}{15}+\dfrac{-1}{9}\)
\(B=\dfrac{6}{45}+\dfrac{-5}{45}\)
\(B=\dfrac{1}{45}\)
\(C=\left(9-\dfrac{1}{5}+\dfrac{3}{12}\right)+\dfrac{-3}{4}\)
\(C=\left(\dfrac{44}{5}+\dfrac{1}{4}\right)+\dfrac{-3}{4}\)
\(C=\dfrac{181}{20}+\dfrac{-3}{4}\)
\(C=\dfrac{181}{20}+\dfrac{-15}{20}\)
\(C=\dfrac{166}{20}\)
Bài 6:
\(a)x+\dfrac{7}{8}=\dfrac{13}{12}\)
⇔\(x=\dfrac{13}{12}-\dfrac{7}{8}=\dfrac{5}{24}\)
\(b)\dfrac{-6}{12}-x=\dfrac{9}{48}\)
⇔\(x=\dfrac{-6}{12}-\dfrac{9}{48}=\dfrac{-11}{16}\)
\(c)x+\dfrac{4}{6}=\dfrac{5}{25}-\dfrac{-7}{15}\)
\(\Leftrightarrow x+\dfrac{2}{3}=\dfrac{2}{3}\)
\(\Leftrightarrow x=\dfrac{2}{3}-\dfrac{2}{3}=0\)
\(d)x+\dfrac{4}{5}=\dfrac{6}{20}-\dfrac{-7}{3}\)
⇔\(x+\dfrac{4}{5}=\dfrac{79}{30}\)
⇔\(x=\dfrac{79}{30}-\dfrac{4}{5}=\dfrac{11}{6}\)
Tính giá trị biểu thức :
A = 6/8 . 8/13 + 6/13 . 9/7 - 3/13 . 6/7
B = ( 5/4 + 3/4 ) . 4/7 . ( 3/4 + 9/4 ) . 4/7
C = -5/7 . 1/35 + 6/49 . ( -8 ) + 16/(-3) . (-3)/8
D = ( 5/10 + 21/28 - 60/72 ) . 24/5
các bạn làm ơn giúp mình với đc ko , mình đang cần gấp !!!!
Trả lời:
\(A=\frac{6}{8}.\frac{8}{13}+\frac{6}{13}.\frac{9}{7}-\frac{3}{13}.\frac{6}{7}\)
\(A=\frac{6}{13}+\frac{54}{91}-\frac{18}{91}\)
\(A=\frac{6}{7}\)
\(B=\left(\frac{5}{4}+\frac{3}{4}\right).\frac{4}{7}.\left(\frac{3}{4}+\frac{9}{4}\right).\frac{4}{7}\)
\(B=\frac{2}{1}.\frac{4}{7}.\frac{3}{1}.\frac{4}{7}\)
\(B=\frac{8}{7}.\frac{12}{7}\)
\(B=\frac{96}{49}\)
Tính giá trị của biểu thức:
A = 7/(3*4) - 9/(4*5) + 11/(5*6) - 13/(6*7) + 15/(7*8) - 17/(8*9) + 19/(9*10)
tính giá trị biểu thức a7/8 x 3 + 5/12 b. 4/5+ 7/10 c . 6/9 : (2/3 :3
\(a,\dfrac{4}{5}+\dfrac{7}{10}=\dfrac{8}{10}+\dfrac{7}{10}=\dfrac{15}{10}=\dfrac{3}{2}\\ b,\dfrac{7}{8}\times3+\dfrac{5}{12}=\dfrac{21}{8}+\dfrac{5}{12}=\dfrac{21\times3+5\times2}{24}=\dfrac{73}{24}\\ c,\dfrac{6}{9}:\left(\dfrac{2}{3}:3\right)=\dfrac{2}{3}:\dfrac{2}{3}\times3=1\times3=3\)
4. Tính giá trị của biểu thức: A) 7/20 - ( 5/8 - 2/5 ). B) 5/6 + ( 5/9 - 1/4 ). C) 9/10 - ( 2/5 - 3/10 ) + 7/20.
A)\(\dfrac{7}{20}-\left(\dfrac{5}{8}-\dfrac{2}{5}\right)\)
\(=\dfrac{7}{20}-\left(\dfrac{25}{40}-\dfrac{16}{40}\right)\)
\(=\dfrac{7}{20}-\dfrac{9}{40}\)
\(=\dfrac{14}{40}-\dfrac{9}{40}=\dfrac{5}{40}=\dfrac{1}{8}\)
B) \(\dfrac{5}{6}+\left(\dfrac{5}{9}-\dfrac{1}{4}\right)\)
\(=\dfrac{5}{6}+\left(\dfrac{20}{36}-\dfrac{9}{36}\right)\)
\(=\dfrac{5}{6}+\dfrac{11}{36}\).
\(=\dfrac{30}{36}+\dfrac{11}{36}=\dfrac{41}{36}\)
C) \(\dfrac{9}{10}-\left(\dfrac{2}{5}-\dfrac{3}{10}\right)+\dfrac{7}{20}\)
\(=\dfrac{9}{10}-\left(\dfrac{4}{10}-\dfrac{3}{10}\right)+\dfrac{7}{20}\)
\(=\dfrac{9}{10}-\dfrac{1}{10}+\dfrac{7}{20}\)
\(=\dfrac{18}{20}-\dfrac{2}{20}+\dfrac{7}{20}=\dfrac{23}{20}\)
a: =7/20-5/8+2/5
=14/40-25/40+16/40
=5/40=1/8
b: =5/6+5/9-1/4
=30/36+20/36-9/36
=41/36
c: =9/10-2/5+3/10+7/20
=12/10-2/5+7/20
=7/20+6/5-2/5
=7/20+4/5
=7/20+16/20
=23/20
tính giá trị biểu thức sau(tính nhanh nếu có thể)
a)3^3.9-3^4.3+5^8.5^0-5^12:25^2
b)A=(25^6+15^6-10^6):5^6
c)B=9!-8!-7!.8^2