15/34+7/21+9/34-32/17+2/3
15/34+7/21+19/34-32/17+2/3
\(\dfrac{15}{34}+\dfrac{7}{21}+\dfrac{19}{34}-\dfrac{32}{17}+\dfrac{2}{3}\)
\(=\left(\dfrac{15}{34}+\dfrac{19}{34}\right)+\dfrac{7}{21}+\dfrac{-32}{17}+\dfrac{2}{3}\)
\(=1+\dfrac{1}{3}+\dfrac{-32}{17}+\dfrac{2}{3}\)
\(=1+\left(\dfrac{1}{3}+\dfrac{2}{3}\right)+\dfrac{-32}{17}\)
\(=1+1+\dfrac{-32}{17}\)
\(2+\dfrac{-32}{17}=\dfrac{2}{17}\)
`15/34+7/21+9/34-1 15/17+2/3`
`=(15/34+9/34)+(7/21+2/3)-32/17`
`=12/17+1-32/17`
`=(12/17-32/17)+1`
`=-20/17+1`
`=-3/17`
\(\dfrac{15}{34}+\dfrac{7}{21}+\dfrac{9}{34}-1\dfrac{15}{17}+\dfrac{2}{3}\)
\(=\left(\dfrac{15}{34}+\dfrac{9}{34}-\dfrac{32}{17}\right)+\left(\dfrac{1}{3}+\dfrac{2}{3}\right)\)
\(=-\dfrac{25}{17}+1=-\dfrac{8}{17}\)
A=15\34 +7\21 + 9\34-15\17+2\3
=(15/34+9/34-15/17)+(1/3+2/3)
=(24/34-15/17)+1
=-3/17+1
=14/17
A = 15/34 + 7/21 + 9/34 - 1l15/17 + 2/3
Sửa đề:
\(A=\dfrac{15}{34}+\dfrac{7}{21}+\dfrac{9}{34}-1\dfrac{15}{17}+\dfrac{2}{3}\)
\(=\dfrac{15}{34}+\dfrac{7}{21}+\dfrac{9}{34}-\dfrac{32}{17}+\dfrac{2}{3}\)
\(=-\dfrac{3}{17}\)
Tính nhanh :A=\(\dfrac{15}{34}+\dfrac{7}{21}+\dfrac{9}{34}-1\dfrac{15}{17}+\dfrac{2}{3}\)
\(A=\dfrac{15}{34}+\dfrac{1}{3}+\dfrac{9}{34}-\dfrac{32}{17}+\dfrac{2}{3}\)
\(A=\dfrac{15}{34}+\dfrac{1}{3}+\dfrac{9}{34}-\dfrac{64}{34}+\dfrac{2}{3}\)
\(A=\left(\dfrac{15}{34}+\dfrac{9}{34}-\dfrac{64}{34}\right)+\left(\dfrac{1}{3}+\dfrac{2}{3}\right)\)
\(A=\dfrac{40}{34}+1=2\dfrac{6}{34}\)
\(A=\dfrac{15}{34}+\dfrac{7}{21}+\dfrac{9}{34}-1\dfrac{15}{17}+\dfrac{2}{3}\)
\(=\dfrac{15}{34}+\dfrac{1}{3}+\dfrac{9}{34}-1\dfrac{15}{17}+\dfrac{2}{3}\)
\(=\left(\dfrac{15}{34}+\dfrac{9}{34}\right)+\left(\dfrac{1}{3}+\dfrac{2}{3}\right)-1\dfrac{15}{17}\)
\(=1+1-1\dfrac{15}{17}\)
\(=2-1\dfrac{15}{17}\)
\(=\dfrac{2}{17}\)
1, Thực hiện phép tính :
A = 15/34 + 7/21 + 9/34 - 32/17 + 2/3
B = 114/7 : ( - 3/5) - 198/7 : (-3/5)
C = 25 . ( -1/3 ) + 1/5 - 2.(-1/2)^2 - 1/2
D = ( -2)^3 . ( 3/4 - 0,25 ) : ( 9/4 - 7/6 )
Giúp mình nhé ! cảm ơn các bạn !
\(\dfrac{15}{34}-\dfrac{7}{21}+\dfrac{19}{34}-\dfrac{15}{17}-\dfrac{2}{3}\)
\(\dfrac{15}{34}-\dfrac{7}{21}+\dfrac{19}{34}-\dfrac{15}{17}-\dfrac{2}{3}\)
\(=\left(\dfrac{15}{34}+\dfrac{19}{34}\right)-\left(\dfrac{7}{21}+\dfrac{2}{3}\right)-\dfrac{15}{17}\)
\(=1-\left(\dfrac{7}{21}+\dfrac{14}{21}\right)-\dfrac{15}{17}\)
\(=1-1-\dfrac{15}{17}\)
\(=-\dfrac{15}{17}\)
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26+27+28+29+30+31+32+33+34+35+36+37=
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26+27+28+29+30+31+32+33+34+35+36+37
=(1+37)x37:2
=703
So sánh :
a)-3/17 và -2/11
b)15/-21 và -7/10
c)-34/25 và -32/27