{ 240 - [ 76 - ( 9 - 3 )2 ] } : 50
tìm x
( 2 + x ) : 5 = 6
2 + x : 5 = 6
so sánh
a. 12580 và 25118
b. 1340 và 2161
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1:
a: Vì \(\dfrac{-4}{3}=\dfrac{-4\cdot3}{3\cdot3}=\dfrac{-12}{9}=\dfrac{12}{9}\\ \Rightarrow\dfrac{-4}{3}=\dfrac{12}{9}\)
b: Vì : \(-2\cdot3=-6\\ -6\cdot8=-48\)
nên 2 p/s ko bằng nhau
TL :
1) 112 x 5 x 2
= 112 x 10
=1120
2) 2 x 247 x 5
= 247 x 10
= 2470
3) 2 x 4 x 3 x 5
= 12 x 10
= 120
4) 20 x 7 x 5 x 8
= 100 x 56
= 5600
5) 25 x 35 x 4
= 100 x 35
= 3500
6) 47 x 7 + 47 x 3
= 47 x ( 7 + 3 )
= 47 x 10
= 470
7) 5 x 7 x 9 x 2
= 10 x 63
= 630
8) 125 x 9 x 7 x 8
= 1000 x 63
= 63000
9) 4 x 97 x 25
= 100 x 97
= 9700
10) 8 x 9 x 10 ( chắc thế )
= 80 x 9
= 720
11) 240 x 24 + 240 x 24
= 24 x ( 240 + 240 )
= 24 x 480
= 11520
12) 27 x 2 + 27 x 3 + 27 x 5
= 27 x ( 2 + 3 + 5 )
= 27 x 10
= 270
13) 48 x 4 + 48 x 3 + 48 x 2 + 48
= 48 x 4 + 48 x 3 + 48 x 2 + 48 x 1
= 48 x ( 4 + 3 + 2 + 1 )
= 48 x 10
= 480
14) 247 x 36 + 247 x 64
= 247 x ( 36 + 64 )
= 247 x 100
= 24700
15) 76 x 6 + 76 x 4
= 76 x ( 6 + 4 )
= 76 x 10
= 760
16) 249 x 101 - 249
= 249 x 101 - 249 x 1
= 249 x ( 101 - 1 )
= 249 x 100
= 24900
Mong các ban cho tui 10 cái T I C K
~HT~
\(a,2^{300}=\left(2^3\right)^{100}=8^{100}\)
\(3^{200}=\left(3^2\right)^{100}=9^{100}\)
Vì \(8^{100}< 9^{100}\) nên \(2^{300}< 3^{200}\)
\(b,8^5=32768\)
\(6^6=46656\)
Vì \(32768< 46656\) nên \(8^5< 6^6\)
\(c,3^{450}=\left(3^3\right)^{150}=27^{150}\)
\(5^{300}=\left(5^2\right)^{150}=25^{150}\)
Vì \(27^{150}>25^{150}\) nên \(3^{450}>5^{300}\)
#Ayumu
\(\left(x\times1\right)+\left(x\times2\right)+\left(x\times3\right)+....+\left(x\times10\right)=240\)
\(\left(x\times x\times x\times....\times x\right)\times\left(1+2+3+...+10\right)=240\)
\(1x\times\frac{\left(10+1\right).10}{2}=240\)
\(1x\times55=240\)
\(1x=240\div55\)
\(1x=\frac{48}{11}\)
\(\Rightarrow x=\frac{48}{11}\)
\(240:\left(5^3-5^3:5^2\right)-3^6:3^4+15\cdot11\cdot\left(13-9\right)\)
\(=240:\left(5^3-5\right)-3^{6-4}+15\cdot11\cdot4\)
\(=240\cdot\left(125-5\right)-3^2+60\cdot11\)
\(=240:120-9+60\cdot\left(10+1\right)\)
\(=2-9+600+60\)
\(=653\)
\(1,\\ a,2< 3\Rightarrow2^{30}< 3^{30}\Rightarrow-2^{30}>-3^{30}\\ b,6^{10}=6^{2\cdot5}=\left(6^2\right)^5=36^5>35^5\left(36>35\right)\)
\(2,\\ a,\dfrac{\left(-3\right)^{10}\cdot15^5}{25^3\cdot\left(-9\right)^7}=\dfrac{3^{10}\cdot5^5\cdot3^5}{5^6\cdot3^{14}}=\dfrac{3}{5}\\ b,\left(8x-1\right)^{2x+1}=5^{2x+1}\\ \Leftrightarrow8x-1=5\\ \Leftrightarrow x=\dfrac{3}{4}\)
Bài 2:
a: Ta có: \(\dfrac{\left(-3\right)^{10}\cdot15^5}{25^3\cdot\left(-9\right)^7}\)
\(=\dfrac{-3^{10}\cdot3^5\cdot5^5}{5^6\cdot3^{14}}\)
\(=-\dfrac{3}{5}\)
b: Ta có: \(\left(8x-1\right)^{2x+1}=5^{2x+1}\)
\(\Leftrightarrow8x-1=5\)
\(\Leftrightarrow8x=6\)
hay \(x=\dfrac{3}{4}\)
\(\left\{240-\left[76-\left(9-3\right)^2\right]\right\}\div50=\left\{240-\left[76-6^2\right]\right\}\div50=\left\{240-\left[76-36\right]\right\}\div50\)
\(=\left\{240-40\right\}\div50=200\div50=4\)
Tìm x :
\(\left(2+x\right)\div5=6\)
\(2+x=6.5\)
\(2+x=30\)
\(x=30-2\)
\(x=28\)
\(2+x\div5=6\)
\(x\div5=6-2\)
\(x\div5=4\)
\(x=4.5\)
\(x=20\)
So sánh :
a) Ta có : \(125^{80}=\left(5^3\right)^{80}=5^{240}\)
\(25^{118}=\left(5^2\right)^{118}=5^{236}\)
mà \(240>236\)
\(\Rightarrow5^{240}>5^{236}\)
\(\Rightarrow125^{80}>25^{118}\)
b) Ta có : \(2^{161}>2^{160}=\left(2^4\right)^{40}=16^{40}>13^{40}\)
\(\Rightarrow2^{161}>13^{40}\)