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1+3+5+7+..................+193
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a, \(-7.\left|x-2013\right|+2012^0=\left|+1\right|\)
AI NHANH VA DUNG THI MK SE TICK CHO NHA^_^
a) \(-7.\left|x-2013\right|+2012^0=\left|+1\right|\)
\(\Leftrightarrow-7.\left|x-2013\right|+1=1\)
\(\Leftrightarrow-7.\left|x-2013\right|=0\)
\(\Leftrightarrow\left|x-2013\right|=0\)
\(\Leftrightarrow x-2013=0\)
\(\Leftrightarrow x=2013\)
Vậy x = 2013
a) -7.|x-2013| + 20120 = |+1|
-7.|x-2013| + 1 = 1
=> -7.|x-2013| = 0
=> | x-2013| = 0
=> x - 2013 = 0
x = 2013
a) \(\left(7x-11\right)^3=2^5.5^2+200\)
\(\Rightarrow\left(7x-11\right)^3=32.25+200\)
\(\Rightarrow\left(7x-11\right)^3=800+200\)
\(\Rightarrow\left(7x-11\right)^3=1000\)
\(\Rightarrow\left(7x-11\right)^3=10^3\)
\(\Rightarrow7x-11=10\)
\(\Rightarrow7x=10+11\)
\(\Rightarrow7x=21\)
\(\Rightarrow x=21:7\)
\(\Rightarrow x=3\)
Vậy x = 3
b) \(\left(2x-15\right)^5=\left(2x-15\right)^3\)
\(\Rightarrow\left(2x-15\right)^5-\left(2x-15\right)^3=0\)
\(\Rightarrow\left(2x-15\right)^3\left[\left(2x-15\right)^2-1\right]=0\)
\(\Rightarrow\orbr{\begin{cases}\left(2x-15\right)^3=0\\\left(2x-15\right)^2-1=0\end{cases}}\Rightarrow\orbr{\begin{cases}\left(2x-15\right)^3=0\\\left(2x-15\right)^2=1\end{cases}}\)
TH 1 : \(\left(2x-15\right)^3=0\Rightarrow2x-15=0\Rightarrow2x=15\Rightarrow x=\frac{15}{2}\)
TH 2 : \(\left(2x-15\right)^2=1\Rightarrow\orbr{\begin{cases}2x-15=1\\2x-15=-1\end{cases}}\Rightarrow\orbr{\begin{cases}2x=16\\2x=14\end{cases}}\Rightarrow\orbr{\begin{cases}x=8\\x=7\end{cases}}\)
Vậy \(x\in\left\{\frac{15}{2};8;7\right\}\)
_Chúc bạn học tốt_
a) -79.|-45| - 21.|+45|
= -79.45 - 21.45
= 45. (-79-21)
= 45. (-100)
= -4500
b) 29.(23+15) - 23.(29+15)
= 29.23 + 29.15 - 23.29 - 23.15
= (29.23 - 23.29) + (29.15 - 23.15)
= 0 + 15.(29-23)
= 15.6
= 90
\(1-2+3-4+5-\)\(6+....+99-100+101\)
\(=\left(1-2\right)+\left(3-4\right)+\left(5-6\right)+...+\left(99-100\right)+101\)
\(=\left(-1\right)+\left(-1\right)+\left(-1\right)+...+\left(-1\right)+101\)
\(=\left(-1\right).50+101\)
\(=\left(-50\right)+101\)
\(=51\)
a) 4.52-3.23 = 22.52-3.23 = 22.(52-3.2) =22.(25-6) = 4.19 = 76
b) 28.76 + 13.28 + 9.2
= 28. (76 + 13) + 18
= 28. 89 + 18
= 2492 + 18
= 2510
c) 1024: ( 17 .25+15.25)
= 210 : [25.(17+15)]
= 210: [25. 32]
= 210: [25.25)
= 210:210
= 1
a) 4.52-3.23
=22.52-3.23
=22.(25-6)
=4.11
=44
b) 28.76+13.28+9.2
=28.(76+13)+9.2
=28.89+9.2
=2.(1246+9)
=2.1255
=2510
c) 1024:(17.25+15.25)
=1024:25.(17+15)
=1024:32.32
=1
a. -234 + 145 + (-2013) + 155 +(-66) = -2013
b. -95.(-454)-456.95= 95.(454 -456) = -190
Ý bạn là sao?= 193 à
1+3+5+7+...+193
= (193+1).97 : 2
= 194.97 .1/2
= 97.(194.1/2)
= 97.97
= 9409