(3x – 24).73 = 2.74
(3x – 24 ).73= 2.74
\(\Leftrightarrow3x-16=2\cdot7=14\)
hay x=10
Bài 8. Tìm x ϵ N biết:
a) x3=27
b) (2x-1)3=8
c) (x-2)2=16
d) (2x – 3)2=9
e) 2x+5=34:32
f) (3x-24).73=2.74
Bài 8. Tìm x ϵ N biết:
a) x3=27
b) (2x-1)3=8
c) (x-2)2=16
d) (2x – 3)2=9
e) 2x+5=34:32
f) (3x-24).73=2.74
130+x=154
140:(x-8)=-7
(x+24).73=2.74
c: \(\Leftrightarrow x+16=2\cdot7=14\)
hay x=-2
Tìm x biết:
a)58+7x=100
b)3x - 7=28
c)x - 56:4=16
d)101+(36-4x)=105
e) (x - 12 ) : 12 = 12
f) (3.x-24).73=2.74
i) (10+2x) .42011=42013
a) \(58+7x=100\)
\(=>7x=100-58\)
\(=>7x=42\)
\(=>x=42:7\)
\(=>x=6\)
b) \(3x-7=28\)
\(=>3x=28+7\)
\(=>3x=35\)
\(=>x=35:3\)
\(=>x=\dfrac{35}{3}\)
c) \(x-56:4=16\)
\(=>x-14=16\)
\(=>x=16+14\)
\(=>x=30\)
d) \(101+\left(36-4x\right)=105\)
\(=>36-4x=105-101\)
\(=>36-4x=4\)
\(=>4x=36-4\)
\(=>4x=32\)
\(=>x=32:4\)
\(=>x=8\)
e) \(\left(x-12\right):12=12\)
\(=>x-12=12.12\)
\(=>x-12=144\)
\(=>x=144-12\)
\(=>x=132\)
f) \(\left(3x-2^4\right).7^3=2.7^4\)
\(=>3x-2^4=2.7^4:7^3\)
\(=>3x-16=2.7=14\)
\(=>3x=14+16\)
\(=>3x=30\)
\(=>x=30:3\)
\(=>x=10\)
i) \(\left(10+2x\right).4^{2011}=4^{2013}\)
\(=>10+2x=4^{2013}:4^{2011}\)
\(=>10+2x=4^2=16\)
\(=>2x=16-10\)
\(=>2x=6\)
\(=>x=6:2\)
\(=>x=3\)
\(#WendyDang\)
tìm số tự nhiên x
(5.x-24).73=2.74
giải kĩ giúp mình
\(\left(5x-24\right).73=2.74\)
\(\Leftrightarrow\left(5x-24\right).73=148\)
\(\Leftrightarrow5x-24=\frac{148}{73}\)
\(\Leftrightarrow5x=\frac{148}{73}+24\)
\(\Leftrightarrow5x=\frac{1900}{73}\)
\(\Leftrightarrow x=\frac{1900}{73}.\frac{1}{5}\)
\(\Leftrightarrow x=\frac{380}{73}\)
(5.x-24).73=148
5.x-24=148:73
5.x-24=148/73
5.x=148/73+24
5.x=1900/73
x=1900/73:5
x=1900/73.1/5
x=380/73
X-7 = -5 (x+2) = 0 (3x - 24) . 73 =2.74 | x - 5 | = |-7| x- [42 + ( -28) = -8 ( 7x - x ) - ( 25+7 ) = -25 |x-3| = |5| + | -7 | ( x : 3-4 ) : 5 =15 | x -3 | = 7 - (-2) 128 -3 . (x+4) = 23 4 - ( 7-x ) = x - (13-4 ) BÀI 2 : TÍNH NHANH S1 = 1+2+3+.......999 S1= 10 +12 + 14 +.......2010 S3 + 21 + 23 + 25 + .......10001
1.
a) 2x + 5 = 34 : 32
b) ( 3x - 24 ) . 73 = 2.74
c) [ 3 . ( 42 - x ) + 15 = 23 . 3
d) 126 + ( 132 - x ) = 300
2.
a) 120 - ( x + 55 ) = 60
b) ( 7x - 11)3 = 25 .52 + 200
c) 2x + 2x+4 = 544
3.
a) 10 + 2x = 49 : 47
b) 70 - 5 ( x - 3 ) = 45
c) 4 + 95 : x = 143 : 142 - 23
1)
a) 2x + 5 = 3⁴ : 3²
2x + 5 = 3²
2x + 5 = 9
2x = 9 - 5
2x = 4
x = 4 : 2
x = 2
b) (3x - 24).73 = 2.74
(3x - 24).73 = 148
3x - 24 = 148/73
3x = 148/73 + 24
3x = 1900/73
x = 1900/73 : 3
x = 1900/219
c) [3.(42 - x)] + 15 = 23.3
126 - 3x + 15 = 69
141 - 3x = 69
3x = 141 - 69
3x = 72
x = 72 : 3
x = 24
d) 126 + (132 - x) = 300
132 - x = 300 - 126
132 - x = 174
x = 132 - 174
x = -42
2)
a) 120 - (x + 55) = 60
x + 55 = 120 - 60
x + 155 = 60
x = 60 - 55
x = 5
b) (7x - 11).3 = 25.52 + 200
(7x - 11).3 = 1500
7x - 11 = 1500 : 3
7x - 11 = 500
7x = 500 + 11
7x = 511
x = 511 : 7
x = 73
c) 2x + 2x + 4 = 544
4x = 544 - 4
4x = 540
x = 540 : 4
x = 135
3)
a) 10 + 2x = 49 : 47
10 + 2x = 49/47
2x = 49/47 - 10
2x = -421/47
x = -421/47 : 2
x = -421/94
b) 70 - 5(x - 3) = 45
5(x - 3) = 70 - 45
5(x - 3) = 25
x - 3 = 25 : 5
x - 3 = 5
x = 5 + 3
x = 8
c) 4 + 95 : x = 143 : 142 - 23
4 + 95 : x = -3123/142
95 : x = -3123/142 - 4
95 : x = -3691/142
x = 95 : (-3691/142)
x = -13490/3691
(3x-2^4).7^3=2.74
(3x-24) . 73 = 2.74
(3x-16). 343 = 148
3x - 16 =148: 343
3x - 16 = \(\frac{148}{343}\)
3x = \(\frac{148}{343}\) +16
3x =\(\frac{4036}{343}\)
x = \(\frac{4036}{343}\) : 3
x = \(\frac{4036}{1029}\)
Vậy x = \(\frac{4036}{1029}\)
10) x - [42 + (-28)] = -8
11) (7 - x) - (25 + 7)=- 25
12) (3x - 24). 73 = 2.74
13) ( x – 4)² = 25
14) 24( 2x + 11)² = 42
15) 73x-2 – 3.73 =73 . 4
\(10,\Rightarrow x-14=-8\Rightarrow x=6\\ 11,\Rightarrow7-x-32=-25\\ \Rightarrow-25-x=-25\Rightarrow x=0\\ 12,\Rightarrow3x-16=\dfrac{2\cdot7^4}{7^3}=2\cdot7=14\\ \Rightarrow3x=30\Rightarrow x=10\\ 13,\Rightarrow\left[{}\begin{matrix}x-4=5\\x-4=-5\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=9\\x=-1\end{matrix}\right.\\ 14,\Rightarrow\left(2x+11\right)^2=2^4:2^4=1\\ \Rightarrow\left[{}\begin{matrix}2x+11=1\\2x+11=-1\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=-5\\x=-6\end{matrix}\right.\\ 15,\Rightarrow7^{3x-2}=7^3\cdot4+7^3\cdot3=7^3\cdot7=7^4\\ \Rightarrow3x-2=4\\ \Rightarrow3x=6\Rightarrow x=2\)
10) x - [42 + (-28)] = -8
x - 14 = -8
x = -8 + 14 = 6
11) (7-x) - (25 +7) = -25
(7 -x) - 32 = -25
7 -x = -25 + 32 = 7
x = 7 -7 = 0
12) (3x - 24) . 73 = 2 . 74
(3x - 16) . 343 = 4802
3x - 16 = 4802 : 343= 14
3x = 14 + 16 = 30
x = 30 : 3 =10
13) (x - 4)2 = 25
⇒ 52 = 25
⇒ x - 4 = 5
⇒ x = 5 + 4 =9
14) 24(2x + 11)2 = 42
16(2x + 11)2 = 16
(2x + 11)2 = 16 : 16 = 1
⇒ 2x + 11 = 1
⇒ 2x = 11 + 1 = 12
⇒ x = 12 : 2 = 6
15) 73x-2 - 3.73 = 73 . 4
73x-2 - 1029 = 1372
73x-2 = 1372 + 1029 = 2401
⇒ 74 = 2401
⇒ 3x - 2 = 4
⇒ 3x = 4 + 2 = 6
⇒ x = 6 : 3 =2