tìm x
a)12:x=144
b)x-17=(-2).27
c)3x-125=145
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a) 70 - 5(x - 3 ) = 45
5( x - 3 ) = 70 - 45 = 25
x - 3 = 25 : 5 = 5
x = 5 + 3 = 8
b) (2x - 1 )4 = 3 . 62 - 27
(2x - 1 )4 = 3 . 36 - 27
(2x - 1 )4 = 81
Ta thấy 81 = 34 vậy suy ra (2x - 1)4 = 34
Để vế trong ngoặc tròn (2x - 1 ) = 3 thì x cần bằng 2
Thử lại : 2 . 2 - 1 = 4 - 1 = 3
Vậy x = 2
c) 3x3 + 43 = 102 - 33
3x3 + 43 = 100 - 33 = 67
3x3 = 67 + 43 = 110 ( Đoạn này đề bài sai hay tao sai z :)?)
a) \(\left[\left(x+32\right)-17\right].2=42\)
\(\left[\left(x+32\right)-17\right]=42:2\)
\(\left[\left(x+32\right)-17\right]=21\)
\(\left(x+32\right)=21+17\)
\(\left(x+32\right)=38\)
\(x=38-32\)
\(x=6\)
b) \(125+\left(145-x\right)=175\)
\(\left(145-x\right)=175-125\)
\(\left(145-x\right)=50\)
\(x=145-50\)
\(x=95\)
a, (x + 30) – 75 = 125
=> x + 30 = 125 + 75 = 200
=> x = 200 – 30
=> x = 170
Vậy x = 170
b, x – 72 : 36 = 18
=> x – 2 = 18
=> x = 18 + 2 = 20
Vậy x = 20
c, x – 17 = 54
=> x = 54 +17
=> x = 71.
Vậy x = 71
d, 36 – (x – 2) = 12
=> x – 2 = 36 – 12
=> x = 24 + 2 = 26
Vậy x = 26
e, 9x – 7 = 837
=>9x = 837 + 7 = 844
=> x = 844 9
Vậy x = 844 9
f, (x – 15) – 107 = 0
=> x – 15 = 107
=> x = 107 +15
=> x = 122.
Vậy x = 122
g, 134 + (116 – x) = 145
=> 116 – x = 145 – 134
=> x = 116 – 11
=> x = 5.
Vậy x = 5
Bài 1:
a) −x + 8 = −17
−x = −17 − 8
−x = −25
⇒ x = 25
Vậy x = 25
b) 35 − x = 37
x = 35 − 37
x = −2
Vậy x = −2
c) x − 45 = −17
x = −17 + 45
x = 28
Vậy x = 28
d) |x + 1| = 20 (>0)
TH1: x + 1 = 20 TH2: x + 1 = −20
x = 20 − 1 x = −20 − 1
x = 19 x = −21
Vậy x∈\(\left\{-21;19\right\}\)
e) |x − 3| − 16 = −4
|x − 3| = −4 + 16
|x − 3| = 12 (>0)
TH1: x − 3 = 12 TH2: x − 3 = −12
x = 12+3 x = −12 + 3
x = 15 x = −9
Vậy x∈\(\left\{-9;15\right\}\)
a) (125 -679 + 145 ) - ( 125 - 679 )=125 -679+145-125+679=145
b)(x - 29 ) - ( 17 - 38 ) = -9
<=> x-29 -17+38=-9
<=>x=-1
c)( x + 5 ) + ( x - 9 ) = x + 2
<=>x+5+x-9=x+2
<=>x+x-x=2+9-5
<=>x=6
d) ( 27 - x )+ ( 15 + x ) = x - 24
<=> 27-x+15+x-x=-24
<=> -x=-66
<=>x=66
e) -359 + 181 + ( -123 ) + 350 + ( -172 ) = (181 +350)-(359+172) -123 =531-531-123=-123
f) 13 - 12 + 11 + 10 - 9 + 8 - 7 -6 + 5 - 4 + 3 + 2 -1=( 13 - 12) +11 + (10 - 9)+(8-7)-6+(5-4)+3+(2-1)=1+11+1+1-6+1+3+1=13
a, (125 -679 + 145 ) - ( 125 - 679 )
= 125 - 679 + 145 - 125 + 679
= ( 125 - 125 ) + ( -679 + 679 ) + 145
= 0 + 0 +145
= 145
b, (x - 29 ) - ( 17 - 38 ) = -9
x - 29 - 17 + 38 = -9
x - 29 - 17 = -9 - 38
x - 29 - 17 = -47
x - 29 = -47 + 17
x - 29 = -30
x = -30 + 29
x = -1
Vậy x = -1
c, ( x + 5 ) + ( x - 9 ) = x + 2
x + 5 + x - 9 = x + 2
x - x + 14 = x + 2
14 = x + 2
x = 14 - 2
x = 12
Vậy x = 12
d, ( 27 - x )+ ( 15 + x ) = x - 24
27 - x + 15 + x = x - 24
42 + ( -x + x ) = x - 24
42 = x - 24
x = 24 + 42
x = 66
Vậy x = 66
e, -359 + 181 + ( -123 ) + 350 + ( -172 )
= ( -359 + 350 ) + [ 181 + ( -172 ) ] + ( -123)
= (-9) + 9 + ( -123 )
= 0 + ( -123)
= (-123)
g , 13 - 12 + 11 + 10 - 9 + 8 - 7 -6 + 5 - 4 + 3 + 2 -1
= ( 13 - 12 ) + ( 10 - 9 ) + ( 8 - 7 ) + ( 5 - 4 ) + ( 2 - 1 ) + ( 11 - 6 + 3)
= 1 + 1 + 1 + 1 + 1 + 8
= 1. 5 + 8
= 5 + 8
= 13
1a) 25 .8 - 12.5 + 272 :17 - 8
= 200 - 60 + 16 - 8
= 140+16-8
= 156 - 8
= 148
b) 125: 25 +14 - 142 : 71
= 5 + 14 - 2
= 19 - 2 = 17
c) 13. 17 - 256: 16 + 14 : 7 - 1
= 221 - 16 + 2 - 1
= 205 + 2 - 1
= 207 - 1 = 206
d) 15 . 24 - 14 . 5 (145 : 5 - 27)
= 360 - 70 (29- 27)
= 360 - 70 . 2
= 360 - 140
= 220
2a) 37 + x = 55
x= 55 - 37
x = 18
b) x- 31 = 24
x = 24 + 31
x = 55
c) 21 (x-11) = 21
x - 11 = 21 : 21
x = 1 +11
x = 12
d ) 9. (x - 29)= 0
x - 29 = 0 :9
x = 29
e) (x - 1954) . 5 = 50
x - 1954 = 50 : 5
x = 1964
f ) 30 . 60 - x = 30
1800 - x = 30
x = 1800 - 30
x = 1770
Viết mỏi tay quá huhuh
x - 58 : 2 = 17
x - 29 = 17
x = 17 + 29
x = 46
( x - 58 ) : 2 = 17
x - 58 = 17 x 2
x - 58 = 34
x = 34 + 58
x = 92
125 + ( 145 - x ) = 175
145 - x = 175 - 125
145 - x = 50
x = 145 - 50
x = 95
\(x\times\frac{2}{5}=\frac{4}{5}:\frac{2}{3}\)
\(x\times\frac{2}{5}=\frac{6}{5}\)
\(x=\frac{6}{5}:\frac{2}{5}\)
\(x=3\)
x + 3,75 + 4x = 24,25
x + 4x = 24,25 - 3,75
x * 5 = 20,5
x = 20,5 : 5
x= 4,1
x - 58 : 2 = 17
x - 29 = 17
x = 17 + 29
x = 46
( x - 58 ) : 2 = 17
x - 58 = 17 x 2
x - 58 = 34
x = 34 + 58
x = 92
125 + ( 145 - x ) = 175
145 - x = 175 - 125
145 - x = 50
x = 145 - 50
x = 95
x.2/5=4/5:2/3
x.2/5=6/5
x=6/5:2/5
=3
x + 3,75 + 4x = 24,25
x + 4x = 24,25 - 3,75
x * 5 = 20,5
x = 20,5 : 5
x= 4,1
a: 12:x=144
=>\(x=\dfrac{12}{144}\)
=>\(x=\dfrac{1}{12}\)
b: \(x-17=\left(-2\right)\cdot27\)
=>\(x-17=-54\)
=>\(x=-54+17=-37\)
c: \(3x-125=145\)
=>\(3x=125+145=270\)
=>\(x=\dfrac{270}{3}=90\)
\(a,12:x=144\\ x=\dfrac{12}{144}=\dfrac{1}{12}\\ ---\\ b,x-17=\left(-2\right).27\\ x-17=-54\\ x=-54+17=-37\\ ----\\ 3x-125=145\\ 3x=145+125=270\\ x=\dfrac{270}{3}=90\)