23+ 25+ 27+...+ 245+ 247
Những câu hỏi liên quan
23 247 564 324 - 12 245 678 340
\(\dfrac{29-x}{21}\)+\(\dfrac{27-x}{23}\)+\(\dfrac{25-x}{25}\)+\(\dfrac{23-x}{27}\)+\(\dfrac{21-x}{29}\)=\(\dfrac{(29-x+1}{21}\)+\(\dfrac{(27-x+1)}{23}\)+\(\dfrac{(25-x+1)}{25}\)+\(\dfrac{(23-x+1)}{21}\)=-5 +5
GIẢI nốt hộ mình với ạ
\(\dfrac{29-x}{21}\)+\(\dfrac{27-x}{23}\)+\(\dfrac{25-x}{25}\)+\(\dfrac{23-x}{27}\)=-4
\(\Leftrightarrow\dfrac{29-x}{21}+1+\dfrac{27-x}{23}+1+\dfrac{25-x}{25}+1+\dfrac{23-x}{27}+1=0\)
\(\Leftrightarrow\dfrac{50-x}{21}+\dfrac{50-x}{23}+\dfrac{50-x}{25}+\dfrac{50-x}{27}=0\)
\(\Leftrightarrow\left(50-x\right)\left(\dfrac{1}{21}+\dfrac{1}{23}+\dfrac{1}{25}+\dfrac{1}{27}\ne0\right)=0\Leftrightarrow x=50\)
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\(\dfrac{29-x}{21}+\dfrac{27-x}{23}+\dfrac{25-x}{25}+\dfrac{23-x}{27}=-4\\ \Leftrightarrow\left(\dfrac{29-x}{21}+1\right)+\left(\dfrac{27-x}{23}+1\right)+\left(\dfrac{25-x}{25}+1\right)+\left(\dfrac{23-x}{27}+1\right)=0\\ \Leftrightarrow\dfrac{50-x}{21}+\dfrac{50-x}{23}+\dfrac{50-x}{25}+\dfrac{50-x}{27}=0\\ \Leftrightarrow\left(50-x\right)\left(\dfrac{1}{21}+\dfrac{1}{23}+\dfrac{1}{25}+\dfrac{1}{27}\right)=0\\ \Leftrightarrow50-x=0\left(vì.\dfrac{1}{21}+\dfrac{1}{23}+\dfrac{1}{25}+\dfrac{1}{27}\ne0\right)\\ \Leftrightarrow x=50\)
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-23 / 25 . 10 / 13 + -23 / 25 . 3 / 13 + -27 / 25
\(\frac{-23}{25}.\frac{10}{13}+\frac{-23}{25}.\frac{3}{13}+\frac{-27}{25}\)
= \(\frac{-23}{25}.\left(\frac{10}{13}+\frac{3}{13}\right)+\frac{-27}{25}\)
= \(\frac{-23}{25}.1+\frac{-27}{25}\)
= \(\frac{-23}{25}+\frac{-27}{25}\)
= \(\frac{-50}{25}\)
= \(-2\)
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\(\frac{-23}{25}.\frac{10}{13}+\frac{-23}{25}.\frac{3}{13}+\frac{-27}{25}\)
\(=\frac{-23}{25}\left(\frac{10}{13}+\frac{3}{13}\right)+\frac{-27}{25}\)
\(=\frac{-23}{25}+\frac{-27}{25}=\frac{-50}{25}=-2\)
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-23/25.10/13+-23/25.3/13+-27/25
= -23/25(10/13+3/13)+-27/25
= -23/25.1+-27/25
= -23/25+-27/25
= -2
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Xem thêm câu trả lời
a) frac{x-23}{24}+frac{x-23}{25}frac{x-23}{26}+frac{x-23}{27}Leftrightarrowfrac{x-23}{24}+frac{x-23}{25}-frac{x-23}{26}-frac{x-23}{27}0Leftrightarrowleft(x-23right)left(frac{1}{24}+frac{1}{25}-frac{1}{26}-frac{1}{27}right)0Leftrightarrow x-230( vì frac{1}{24}+frac{1}{25}-frac{1}{26}-frac{1}{27}ne0)Leftrightarrow x23Vậy nghiệm của pt x23
Đọc tiếp
a) \(\frac{x-23}{24}+\frac{x-23}{25}=\frac{x-23}{26}+\frac{x-23}{27}\)
\(\Leftrightarrow\frac{x-23}{24}+\frac{x-23}{25}-\frac{x-23}{26}-\frac{x-23}{27}=0\)
\(\Leftrightarrow\left(x-23\right)\left(\frac{1}{24}+\frac{1}{25}-\frac{1}{26}-\frac{1}{27}\right)=0\)
\(\Leftrightarrow x-23=0\)( vì \(\frac{1}{24}+\frac{1}{25}-\frac{1}{26}-\frac{1}{27}\ne0\))
\(\Leftrightarrow x=23\)
Vậy nghiệm của pt x=23
Bài 10 Tính
a) 23 . 27
b ) - 23 . 27
c) 23 . (-23)
d) ( - 23 ) . ( - 27 )
Bài 11 Tính
a) - 37 ( - 17 ) . ( -94 )+ 35. ( - 9 ) . ( -10 )
b) ( - 25 ) . ( 75 - 45 ) - 75 . ( 45 - 25 )
B10:
a)23.27=621
b)-23.27=-621
c)23.(-23)=529
d)(-23).(-27)=621
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(-90)-(x+10)+100 voi x=-24
[(-25).(-27).(-x)]:y voi x = 4 : y = -9
a-b + 17 + 8 . (-3 ) + b voi a = -15 = 2019
(-99).98.(-97) voi 0
(-25).(-24).(-23).(-22).(-21) voi 0
(245).(-47).(-199) voi (-123).(-315)
jup mik vs tks caccau :> mik bi ngao mon toan lam T_T tks cb da jup m :3
1,
Với x=-24 ta có
(-90)-(x+10)+100
= (-90)-(-24+10)+100
= -90+24-10+100
= (100-90)+(24-10)
= 10+14
= 24
2,
Với x=4, y=-9 ta có
[(-25).(-27).(-x)]:y
= [(-25).(-27).(-4)]:(-9)
= [(-25).(-4).(-27)]:(-9)
= [100.(-27)]:(-9)
= (-2700):(-9)
= 300
3,
Với a=-15, b=2019 ta có
a-b+17+8.(-3)+b
= (-15)-2019+17+8.(-3)+2019
= (-15)-2019+17+(-24)+2019
= (-15)-2019+17-24+2019
= (17-15)+(2019-2019)-24
= 2-24
= -22
\(\frac{29-x}{21}+\frac{27-x}{23}+\frac{25-x}{25}+\frac{23-x}{27}+\frac{21-x}{29}=-5\)-5
\(\frac{29-x}{21}+\frac{27-x}{23}+\frac{25-x}{25}+\frac{23-x}{27}+\frac{21-x}{29}=-5.\)
\(\left(\frac{29-x}{21}+1\right)+\left(\frac{27-x}{23}+1\right)+\left(\frac{25-x}{25}+1\right)+\left(\frac{23-x}{27}+1\right)+\left(\frac{21-x}{29}+1\right)\)\(=0\)
\(\frac{50-x}{21}+\frac{50-x}{23}+\frac{50-x}{25}+\frac{50-x}{27}+\frac{50-x}{29}=0\)
\(\left(50-x\right).\left(\frac{1}{21}+\frac{1}{23}+\frac{1}{25}+\frac{1}{27}+\frac{1}{29}\right)=0\)
=> 50 - x = 0 \(\left(\frac{1}{21}+\frac{1}{23}+\frac{1}{25}+\frac{1}{27}+\frac{1}{29}\ne0\right)\)
=> x = 50
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x-23/24 + x-23/25=x-23/26 + x-23/27