a) [(6x-39):3].28=5628 b)4x3+12=120
c)1500:[(30x+40):x]=30
a)3.2x -3=45
b)4x3 +12=120
c)1500:[(36x+40):x]=30
3.2x—3=45
3.2x=45+3
3.2x=48
2x=48:3
2x=16
x=16:2
x=8
4x .3+12=120
4x.3=120–12
4x.3=108
4x=108:3
4x=36
x=36:4
x=9
\(3.2x-3=45\)
\(3.2x=45+3\)
\(3.2x=48\)
\(2x=\frac{48}{3}\)
\(2x=16\)
\(x=8\)
Vậy \(x=8\)
\(1500:\left[\left(36x+40\right):x\right]=30\)
\(\left(36x+40\right):x=1500:30\)
\(36x+40=50x\)
\(50x-36x=40\)
\(14x=40\)
\(x=\frac{40}{14}\)
\(x=\frac{20}{7}\)
Vậy \(x=\frac{20}{7}\)
a)3.2x-3 = 45
3.(2x-1) = 45
2x-1 = 45 : 3
2x-1 = 15
2x = 16
x = 8
các bài cn lại bn dựa vào phần a mak lm nha!
Tìm x E N biết :
a) 4x^3 + 12 = 120
b)3.2^x - 3 = 45
c)1500:[(30x +40):x]=30
a, \(4x^3+12=120\)
\(\Leftrightarrow4x^3=120-12\)
\(\Leftrightarrow4x^3=108\)
\(\Leftrightarrow x^3=108:4\)
\(\Leftrightarrow x^3=27\)
\(\Leftrightarrow x=3\)
b, \(3.2^x-3=45\)
\(\Leftrightarrow3.2^x=45+3\)
\(\Leftrightarrow3.2^x=48\)
\(\Leftrightarrow2^x=48:3\)
\(\Leftrightarrow2^x=16\)
\(\Leftrightarrow x=4\)
Câu c, bạn làm tương tự nha !
a, 4x^3 + 12 = 120 b,3.2^x-3=45 c, 1500:[(30x +40):x]=30
4x^3=120-12 3.2^x =45+3 (30x +40):x =1500:30
4x^3=108 3.2^x =48 (30x +40):x = 50
x^3=108:4 2^x =48:3 30x:x+40:x = 50
x^3=27 2^x =16 30+40:x=50
=> x^3= 3^3 2^x =2^4 40:x=50-30
=> x = 3 => x =4 40:x= 20
=>x=40:20
=>x=20 ( câu c tui có làm sai thì đừng trách nhé )
Tìm x
4x3 + 12 = 120
3.2x - 3 = 45
1500 : [(30x+40) : x] = 30
Tìm x
4x3 + 12 = 120
3*2x - 3 = 45
1500 : [ ( 30x + 40) : x] =30
giup mình với ,có chi mik t lại cho
\(4x^3+12=120\)
\(\Rightarrow4x^3=108\)
\(\Rightarrow x^3=108:4=27=3^3\)
\(\Rightarrow x=3\)
\(3.2^x-3=45\)
\(\Rightarrow3.2^x=48\)
\(\Rightarrow2^x=16=2^4\Rightarrow x=4\)
\(1500:\left[\left(30x+40\right):x\right]=30\)
\(\Rightarrow\left(30x+40\right):x=50\)
\(\Rightarrow30x:x+40:x=50\)
\(\Rightarrow30+40:x=50\)
\(\Rightarrow40:x=20\Rightarrow x=2\)
Tìm số tự nhiên x biết:
a) x : [(1800 + 600):30] = 560 : (315 – 35)
b) [(250 – 25):15] : x = (450 – 60) : 130
c) [(6x – 72) : 2 – 84].28 = 5628
d) 5x + x – 6 = 12
tìm x
a. 120 + ( 56 - 2x ) .3 = 156
b. 3x - 2^3 = 3^2 + 1^21
c. [( 6x - 72 ) : 2 - 84] 28 = 5628
[(6x - 72) : 2 - 84]. 28 = 5628
=> (6x - 72) : 2 - 84 = 5628 : 28 = 201
=> (6x - 72) : 2 = 201 + 84 = 285
=> 6x - 72 = 285 . 2 = 570
=> 6x = 570 + 72 = 642
=> x = 642 : 6
=> x = 107
\(120+\left(56-2x\right).3=156\)
\(\left(56-2x\right).3=156-120\)
\(\left(56-2x\right).3=36\)
\(56-2x=36:3\)
\(56-2x=12\)
\(2x=56-12\)
\(2x=44\)
\(x=44:2\)
\(x=22\)
a/x=2^8:2^4+3^2.3^3
b/6x-39=5628:28
a) x = 2^8 : 2^4 + 3^2 . 3^3
x = 2^4 + 3^5
x = 16 + 243
x = 259
b) 6x - 39 = 5628 : 28
6x - 39 = 201
6x = 240
x = 40
x-7=-5
|x|=3
|X|+=8
8-x=12
6x-39=5628:28
x - 7 = -5
x = -5 + 7
x = 2
|x| = 3
=> x = 3 hoặc x = -3
bạn coi lại đề nha
8 - x = 12
x = 8 - 12
x = -4
6x - 39 = 5628 : 28
6x - 39 = 201
6x = 201 + 39
6x = 240
x = 240 : 6
x = 40
1) x-7=-5
x= -5 +7
x=2
3) /x/=3
=>x= -3 hoặc x=3
câu 3 sai đề
4) 8-x=12
x=8-12
x= -4
5) 6x-39=5628:28
6x-39=201
6x=201+39=240
x=240:6
x=40
1) Tìm x:
a) 20 - [7.(x - 3) + 4 ]=2
b) [ (6x - 39 ) : 3 ] . 28=5628
[(6x-39):3] . 28 = 5628
(6x - 39) : 3 = 201
6x - 39 = 603
6x = 642
x = 107
a) 7.(x - 3) + 4 = 18
7. (x - 3) = 14
x - 3 = 2
x = 5
b) 2x - 13 = 201
2x = 214
x = 107