[ 8 x - 120 ÷ 4 ] ×3^3=3^6
123-5 (x+4)=38
(3x- 2^4)×7^3=2×7^4
1) 7. (3x+5)+2.(7x+14)=98. 2) 4. (x -5)+3.(x+7)=22
3) 5.(4-x) +7.(x-2)=24. 4) 3.(x -5)+6.(x+3)=12
5) 4-x+5.(x+2)=38. 6) 5.( x-3)+2.(x+8)=22
7) 5.(x-7)+10.(4+x)=20. 8) 4.(x+10)+8.(x-3)=24
9) 4.(5-x)+5.(x-2)=15. 10) 4.(x-1)+3.(x-2)=-1
1) 2(x + 5) + 3(x + 7) = 41
2x + 10 + 3x + 21 = 41
5x + 31 = 41
5x = 10
x = 2
6) 7(x - 1) + 5(3 - x) = 11x - 10
7x - 7 + 15 - 5x = 11x - 10
2x + 8 = 11x - 10
-9x = -18
x = 2
2) 5(x + 6) + 2(x - 3) = 38
5x + 30 + 2x - 6 = 38
7x + 24 = 38
7x = 14
x = 2
7) 4(2 + x) + 3(x - 2) = 12
8 + 4x + 3x - 6 = 12
7x + 2 = 12
7x = 10
x = 10/7
3) 7(5 + x) + 2(x - 10) = 15
35 + 7x + 2x - 20 = 15
9x + 15 = 15
9x = 0
x = 0
8) 5(2 + x) + 4(3 - x) = 10x - 15
10 + 5x + 12 - 4x = 10x - 15
x + 22 = 10x - 15
9x = 37
x = 37/9
4) 3(x + 4) + (8 - 2x) = 22
3x + 12 + 8 - 2x = 22
x + 20 = 22
x = 2
9) 7(x - 2) + 5(3 - x) = 11x - 6
7x - 14 + 15 - 5x = 11x - 6
2x + 1 = 11x - 6
-9x = -7
x = 7/9
5) 4(x + 5) + 3(7 - x) = 49
4x + 20 + 21 - 3x = 49
x + 41 = 49
x = 8
10) 5(3 - x) + 5(x + 4) = 6 + 4x
15 - 5x + 5x + 20 = 6 + 4x
35 = 6 + 4x
4x = 29
x = 29/4
Bài 2. Tìm x biết:
a, 128 - 3(x + 4) = 23 d, 720 : [41 - (2x - 5)] = 2 3 .5
b, [(4x + 28).3 + 55] : 5 = 35 e, 123 – 5.( x + 4 ) = 38
c, (12x - 4 3 ).8 3 = 4.8 4 g, ( 3x – 2 4 ) .7 3 = 2.7 4
a,
128-3x-12=23
3x=128-12-23
3x=93
x=93:3
= 31
b,
(12x+84+55):5=35
12x+84+55=35.5
12x+84+55=175
12x=175-55-84
12x=36
x=36:12
x=3
bài 7
4x3 + 12 = 120
b, ( x - 4 )2 = 64
c, ( x + 1 )3 - 2 = 52
d, 136 - ( x + 5)2 = 100
e, 4x = 16
f, 7x. 3 - 147 = 0
g, 2x+3 - 15 = 17
h, 52x-4. 4 = 102
i, (32 - 4x)(7 - x) = 0
k, ( 8 - x)(10 - 2x) = 0
m, 3x + 3x+1 = 108
n, 5x+2 + 5x+1 = 750
a: \(4x^3+12=120\)
=>\(4x^3=108\)
=>\(x^3=27=3^3\)
=>x=3
b: \(\left(x-4\right)^2=64\)
=>\(\left[{}\begin{matrix}x-4=8\\x-4=-8\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=12\\x=-4\end{matrix}\right.\)
c: (x+1)^3-2=5^2
=>\(\left(x+1\right)^3=25+2=27\)
=>x+1=3
=>x=2
d: 136-(x+5)^2=100
=>(x+5)^2=36
=>\(\left[{}\begin{matrix}x+5=6\\x+5=-6\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=1\\x=-11\end{matrix}\right.\)
e: \(4^x=16\)
=>\(4^x=4^2\)
=>x=2
f: \(7^x\cdot3-147=0\)
=>\(3\cdot7^x=147\)
=>\(7^x=49\)
=>x=2
g: \(2^{x+3}-15=17\)
=>\(2^{x+3}=32\)
=>x+3=5
=>x=2
h: \(5^{2x-4}\cdot4=10^2\)
=>\(5^{2x-4}=\dfrac{100}{4}=25\)
=>2x-4=2
=>2x=6
=>x=3
i: (32-4x)(7-x)=0
=>(4x-32)(x-7)=0
=>4(x-8)*(x-7)=0
=>(x-8)(x-7)=0
=>\(\left[{}\begin{matrix}x-8=0\\x-7=0\end{matrix}\right.\)
=>\(\left[{}\begin{matrix}x=8\\x=7\end{matrix}\right.\)
k: (8-x)(10-2x)=0
=>(x-8)(x-5)=0
=>\(\left[{}\begin{matrix}x-8=0\\x-5=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=8\\x=5\end{matrix}\right.\)
m: \(3^x+3^{x+1}=108\)
=>\(3^x+3^x\cdot3=108\)
=>\(4\cdot3^x=108\)
=>\(3^x=27\)
=>x=3
n: \(5^{x+2}+5^{x+1}=750\)
=>\(5^x\cdot25+5^x\cdot5=750\)
=>\(5^x\cdot30=750\)
=>\(5^x=25\)
=>x=2
tìm x
123 - 5. ( x+4 ) = 38
( 3x - 2^4 ) . 7^3 = 2 . 7^4
123 - 5 . ( x + 4 ) = 38
5 . ( x + 4 ) = 123 - 38
5 . ( x + 4 ) = 85
x + 4 = 85 : 5
x + 4 = 17
x = 17 - 4
x = 13
( 3x - 24 ) . 73 = 2 . 74
( 3x - 16 ) . 343 = 2 . 2401
( 3x - 16 ) . 343 = 4802
3x - 16 = 4802 : 343
3x - 16 = 14
3x = 14 + 16
3x = 30
x = 30 : 3
x = 10
123 - 5( x + 4 ) = 38
=> 5( x + 4 ) = 123 - 38
=> x + 4 = 85 ÷ 5
=> x = 17 - 4
=> x = 13
(3x - 24 ) · 73 = 2·74
=> ( 3x - 16 ) = 2 . 74 ÷ 73
=> 3x - 16 = 14
=> 3x = 16 + 14
=> x = 30 ÷ 3
=> x = 10
Bai 1: tìm x, biết:
A) x/5 - 2/33 + 3/4= 17/60
B) x-3/4= -5/4
C) -2 + 3x = 1/7
D) 1/8 - 7/5 - 2/ = -233/120
G) 8/x = 1/-2
F) 3x/4 = 12/16
Giúp mình
Cảm ơn nhìu☺☺🐧
Tìm x
a, 123 - 5 . ( x + 4 ) = 38
b, ( 3x - 24 ) . 73 = 2 . 74
c, ( x : 3 - 4 ) . 5 = 15
a) 123 - 5 (x + 4) = 38
5 (x + 4) = 123 - 38
5 (x + 4) = 85
x + 4 = 85 : 5
x + 4 = 17
x = 17 - 4
x = 13
b) (3x - 24) . 73 = 2 . 74
3x - 24 = 2 . 74 : 73
3x - 24 = 2 . 7
3x - 16 = 14
3x = 14 + 16
3x = 30
x = 30 : 3
x = 10
c) (x : 3 - 4) . 5 = 15
x : 3 - 4 = 15 : 5
x : 3 - 4 = 3
x : 3 = 3 + 4
x : 3 = 7
x = 7 . 3
x = 21
\(a,123-5.\left(x+4\right)=38\)
\(5.\left(x+4\right)=123-38=85\)
\(x+4=85:5=17\)
\(x=17-4=13\)
a, 123 - 5 . ( x + 4 ) = 38
b, ( 3x - 24 ) . 73 = 2 . 74
c, ( x : 3 - 4 ) . 5 = 15
a)123-5.(x+4)=38
118.(x+4)=38
x+=118-38
x+4=80
x=80-4
x=76
Tính hợp lí:
a) 5/7 + 3/8 + 5/8 + 2/7
b) 38/7 - (24/7 + 3/4)
c) 11/3 : (4/3 x 1/2)
d) (68/7 x 7/9) : 7/68
e) 13/4 : 5/6 + 11/4 : 5/6
f) 7/8 : 8/23 + 7/28 : 8/17
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