7/19 × 8/11 + 7/19× 3/11 +12/19
c=7/19*8/11+7/19*3/11+12/19
\(\frac{7}{19}\times\frac{8}{11}+\frac{7}{19}\times\frac{3}{11}+\frac{12}{19}\)
\(=\frac{7}{19}\times\left(\frac{8}{11}+\frac{3}{11}\right)+\frac{12}{19}\)
\(=\frac{7}{19}\times\frac{11}{11}+\frac{12}{19}\)
\(=\frac{7}{19}\times1+\frac{12}{19}\)
\(=\frac{7}{19}+\frac{12}{19}\)
\(=\frac{19}{19}\)
\(=1\)
Chúc bạn học tốt
A= 7/19-8/11 +7/19 :3/11+12/19
A = (7/19 + 12/9)- 8/11+ 7/19 :3/11
A = 1 - 8/11 + 7/19 : 3/11
A = 3/11 + 7/19 : 3/11
A = 1018/627
tính nhanh
7/11 . 8/19 + 7/19 . 3/11 - 12/19
\(\frac{7}{11}.\frac{8}{19}+\frac{7}{19}.\frac{3}{11}-\frac{12}{19}\)
\(=\frac{56}{209}+\frac{21}{209}-\frac{12}{19}\)
\(=\frac{7}{19}-\frac{12}{19}\)
\(=-\frac{5}{19}\)
kb vs tớ nha
và nhớ ủng hộ nữa đó
Tính hợp lí:
g) \(\dfrac{-3}{4}+\dfrac{2}{7}+\dfrac{-1}{4}+\dfrac{3}{5}+\dfrac{5}{7}\)
h) \(\dfrac{7}{19}.\dfrac{8}{11}+\dfrac{7}{19}.\dfrac{3}{11}-\dfrac{12}{19}\)
i) \(19\dfrac{5}{8}:\dfrac{7}{2013}-26\dfrac{5}{8}:\dfrac{7}{2013}\)
k) \(\dfrac{-5}{12}.\dfrac{2}{11}+\dfrac{-5}{12}.\dfrac{9}{11}+\dfrac{5}{12}\)
g: \(=\dfrac{-3}{4}-\dfrac{1}{4}+\dfrac{5}{7}+\dfrac{2}{7}+\dfrac{3}{5}=\dfrac{3}{5}\)
h: \(=\dfrac{7}{19}\left(\dfrac{8}{11}+\dfrac{3}{11}\right)-\dfrac{12}{19}=\dfrac{7}{19}-\dfrac{12}{19}=-\dfrac{5}{19}\)
i: \(=\dfrac{2013}{7}\left(19+\dfrac{5}{8}-26-\dfrac{5}{8}\right)=\dfrac{2013}{7}\cdot\left(-7\right)=-2013\)
\(E = \frac{7}{19}. \frac{8}{11} + \frac{7}{19}. \frac{3}{11} + \frac{12}{19}\)
E = 7/19 . 8/11 + 7/19 . 3/11 +12/19
= 7/19 . ( 8/11 + 3/11 ) + 12/19
= 7/19 . 11/11 + 12/19
= 7/19 . 1 + 12/19
= 7/19 + 12/19
= 7 + 12 / 19
= 19/19
= 1
Bài 2: Thực hiện phép tính một cách hợp lí
f) \(\dfrac{7}{19}\) . \(\dfrac{8}{11}\) + \(\dfrac{3}{11}\) . \(\dfrac{7}{19}\) +\(\dfrac{-12}{19}\)
i) ( \(\dfrac{3}{8}\) + \(\dfrac{-3}{4}\)+ \(\dfrac{7}{12}\) ) : \(\dfrac{5}{6}\) +\(\dfrac{1}{2}\)
f: \(=\dfrac{7}{19}\left(\dfrac{8}{11}+\dfrac{3}{11}\right)-\dfrac{12}{19}=\dfrac{7}{19}-\dfrac{12}{19}=\dfrac{-5}{19}\)
i: \(=\left(\dfrac{9}{24}-\dfrac{18}{24}+\dfrac{14}{24}\right)\cdot\dfrac{6}{5}+\dfrac{1}{2}=\dfrac{5}{24}\cdot\dfrac{6}{5}+\dfrac{1}{2}\)
=1/4+1/2=3/4
` 7/19 . 8/11 + 3/11 . 7/19 + (-12)/19 `
`= 7/19 . ( 8/11 + 3/11 ) + (-12)/19 `
`= 7/19 . 11/11 + (-12)/19`
`= 7/19 . 1 + (-12)/19 `
`= 7/19 + (-12)/19 `
`= -5/19 `
`( 3/8 + (-3)/4 + 7/12 ) : 5/6 + 1/2`
`= 3/8 + (-3)4 + 7/12 . 6/5 + 1/2`
`= ( 9+(-18) + 14)/24 . 6/5 + 1/2`
`= 5/24 . 6/5 + 1/2`
`= 1/4 + 1/2 `
`= 3/4`
A=\(\frac{7}{19}x\frac{8}{11}x\frac{7}{19}:\frac{3}{11}+\frac{12}{19}\)
\(A=\frac{7}{19}.\frac{8}{11}.\frac{7}{19}:\frac{3}{11}+\frac{12}{19}\)
\(A=\left(\frac{7}{19}\right)^2.\frac{8}{11}.\frac{11}{3}+\frac{12}{19}\)
\(\Rightarrow A=\left(\frac{7}{19}\right)^2.\frac{8}{3}+\frac{12}{19}\)
\(\Rightarrow A=\frac{392}{1083}+\frac{12}{19}\)
\(\Rightarrow A=\frac{1076}{1083}\)
Ta có 27^5=3^3^5=3^15
243^3=3^5^3=3^15
Vậy A=B
2^300=2^(3.100)=2^3^100=8^100
3^200=3^(2.100)=3^2^100=9^100
Vậy A<B
A=\(\frac{7}{19}x\frac{8}{11}x\frac{7}{19}:\frac{3}{11}+\frac{12}{19}\)
\(A=\frac{56}{209}x\frac{7}{19}:\frac{3}{11}+\frac{12}{19}\)
\(A=\frac{392}{3971}:\frac{3}{11}+\frac{12}{19}\)
\(A=\frac{392}{1083}+\frac{12}{19}\)
\(A=\frac{1076}{1083}\)
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
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