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\(\dfrac{3}{17}+\dfrac{-8}{15}+\dfrac{-3}{17}+\dfrac{8}{15}+\dfrac{2018}{2019}=\left(\dfrac{3}{17}-\dfrac{3}{17}\right)+\left(\dfrac{8}{15}-\dfrac{8}{15}\right)+\dfrac{2018}{2019}=\dfrac{2018}{2019}\)
\(\dfrac{3}{17}+\dfrac{-8}{15}+\dfrac{-3}{17}+\dfrac{8}{15}+\dfrac{2018}{2019}\)
\(=0+0+\dfrac{2018}{2019}\)
\(=\dfrac{2018}{2019}\)
`#3107.101107`
\(-16 \div (-8)+5[3-15\div5+2(-3+4)]\)
`= 2 + 5(3 - 3 - 6 + 8)`
`= 2 + 5*(-6 + 8)`
`= 2 + 5*2`
`= 2(5 + 1)`
`= 2*6 = 12`
____
`15*(-236)+15*235`
`= 15 * (-236 + 235)`
`= 15 * (-1)`
`= -15`
____
`237*(-28)+28*137`
`= 28 * (-237 + 137)`
`= 28 * (-100)`
`= -2800`
____
`(-3)*(-17)+3*(120-17)`
`= 3 * 17 + 3 * (120 - 17)`
`= 3 * (17 + 120 - 17)`
`= 3 * 120`
`= 360`
____
`(-8)*72+8*(-19)-(-8)`
`= 8 * (-72) + 8 * (-19) + 8`
`= 8 * (-72 - 19 + 1)`
`= 8 * (-90)`
`= -720`
a)−16÷(−8)+5[3−15÷5+2(−3+4)]
=2+5(3−3−6+8)
=2+5⋅(−6+8)
=2+5⋅2
=2(5+1)
=2⋅6
=12
b)15⋅(−236)+15⋅235
=15⋅(−236+235)
=15⋅(−1)
=−15
c)237⋅(−28)+28⋅137
=28⋅(−237+137)
=28⋅(−100)
=−2800
d)(−3)⋅(−17)+3⋅(120−17)
=3⋅17+3⋅(120−17)
=3⋅(17+120−17)
=3⋅120
=360
e)(−8)⋅72+8⋅(−19)−(−8)
=8⋅(−72)+8⋅(−19)+8
=8⋅(−72−19+1)
=8⋅(−90)
=−720
a: \(=\dfrac{3}{5}:\dfrac{7}{5}=\dfrac{3}{5}\cdot\dfrac{5}{7}=\dfrac{3}{7}\)
b: \(=\dfrac{9}{17}\left(\dfrac{8}{5}-\dfrac{3}{5}\right)+\dfrac{8}{17}\)
=9/17+8/17=1
c: =>x-3/10=7/15*1/5=7/75
=>x=7/75+3/10=59/150
m=3.22+5.(-14)=66+(-70)=-4
n = [(-15+1)(-15+2)].[(-15+3)(-15+4)]....(-15+100)
=[(-14).(-13)].[(-12).(-11)].......85
từ (-15+1)=-14 đến-15+15=0 nhân vs nhau ta dc kết quả mà số dương vì có 14:2=7 (cặp) rồi nhân vs 0 ta dc kết quả là 0.
vì 0 nhân vs số nào cs bằng ko nên n=0
vì 0>-4 nên n>m
ko chắc j mấy
ta có:\(A=\frac{17^{15}+3}{17^{15}-2}=\frac{17^{15}-2+5}{17^{15}-2}=\frac{17^{15}-2}{17^{15}-2}+\frac{5}{17^{15}-2}=1+\frac{5}{17^{15}-2}\)
\(B=\frac{17^{15}}{17^{15}-5}=\frac{17^{15}-5+5}{17^{15}-5}=\frac{17^{15}-5}{17^{15}-5}+\frac{5}{17^{15}-5}=1+\frac{5}{17^{15}-5}\)
vì 1715-2>1715-5
=>\(\frac{5}{17^{15}-2}<\frac{5}{17^{15}-5}\)
=>A<B
\(=\dfrac{8}{23}+\dfrac{3}{19}-\dfrac{15}{17}-\dfrac{2}{17}+\dfrac{15}{23}=\dfrac{3}{19}\)
\(\left(\dfrac{8}{23}+\dfrac{3}{19}-\dfrac{15}{17}\right)-\left(\dfrac{2}{17}-\dfrac{15}{23}\right)\\ =\dfrac{8}{23}+\dfrac{3}{19}-\dfrac{15}{17}-\dfrac{2}{17}+\dfrac{15}{23}\\ =\left(\dfrac{8}{23}+\dfrac{15}{23}\right)-\left(\dfrac{15}{17}+\dfrac{2}{17}\right)+\dfrac{3}{19}\\ =1-1+\dfrac{3}{19}\\ =\dfrac{3}{19}\)
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