Tim x biet a,2:(x-1)=9 b,156-(x+61)=82 c,13+(x-1)=6
tim so tu nhien x biet
a) (x-35)-120=0
b)124+(118-x)=217
c) 156-(x+61)=82
a) \(\left(x-35\right)-120=0\)
\(\Rightarrow x-35=120\)
\(\Rightarrow x=120+35\)
\(\Rightarrow x=155\)
b) \(124+\left(118-x\right)=217\)
\(\Rightarrow118-x=93\)
\(\Rightarrow x=25\)
c) \(156-\left(x+61\right)=82\)
\(\Rightarrow x+61=74\)
\(\Rightarrow x=13\)
a) ( x - 35 ) - 120 =0
x - 35 = 0 + 120
x - 35 = 120
x = 120 + 35
x = 155
b) 124 + ( 118 - x ) = 217
118 - x = 217 - 124
118 - x = 93
x = 118 - 93
x = 25
c) 156 - ( x + 61 ) = 82
x + 61 = 156 - 82
x + 61 = 74
x = 74 - 61
x = 13
bài 13: tìm x biết
a. 124 + (118 - x) = 217
b. 156- (x + 61) = 82
c. 219 - 7(x + 1) = 100
d. (3x - 6). 3 = 3^4
e. 231 - (x - 6) = 1339 : 13
a) 124 + (118 - x) = 217
118 - x = 217 - 124
118 - x = 93
x = 118 - 93
x = 25
b) 156 - (x + 61) = 82
x + 61 = 156 - 82
x + 61 = 74
x = 74 - 61
x = 13
c) 219 - 7(x + 1) = 100
7(x + 1) = 219 - 100
7(x + 1) = 119
x + 1 = 119 : 7
x + 1 = 17
x = 17 - 1
x = 16
d) (3x - 6).3 = 3⁴
3x - 6 = 3⁴ : 3
3x - 6 = 3³
3x - 6 = 27
3x = 27 + 6
3x = 33
x = 33 : 3
x = 11
e) 231 - (x - 6) = 1339 : 13
231 - (x - 6) = 103
x - 6 = 231 - 103
x - 6 = 128
x = 128 + 6
x = 134
a) 124 + (118 - x) = 217
118 - x = 217 - 124
118 - x = 93
x = 118 - 93
x = 25
b) 156 - (x + 61) = 82
x + 61 = 156 - 82
x + 61 = 74
x = 74 - 61
x = 13
c) 219 - 7(x + 1) = 100
7(x + 1) = 219 - 100
7(x + 1) = 119
x + 1 = 119 : 7
x + 1 = 17
x = 17 - 1
x = 16
d) (3x - 6) . 3 = 34
(3x - 6) . 3 = 81
(3x - 6) = 81 : 3
(3x - 6) = 27
3x = 27 + 6
3x = 33
x = 33 : 3
x = 11
e) 231 - (x - 6) = 1339 : 13
231 - (x - 6) = 103
(x - 6) = 231 - 103
x - 6 = 128
x = 128 + 6
x = 134
cô cấm dùng máy tính -)
lớp 9 ms đc dùng:_)
a) 156-(x+61)=82 b) (x-35)-120=0 c) 124-(x-118)=217 d) 2x-49=5.3^2 e) 200-(2x+6)=4^3 f) 2(x-51)=2.2^3+20 g) 4(x-3)=7^2-1^10 h) 3^2(x+4)-5^2=5.2^2 i) 9^x-1=9
Tim so tu nhiên x,biết
A) (x-35)-120=0
B) 156-(x+61)=82
C) 124+(118-x)=217
a. (x-35)-120=0
=> x-35 = 0+120
=> x-35 = 120
=> x = 120+35
=> x = 155
b. 156-(x+61)=82
=> x+61=156-82
=> x+61=74
=> x = 74-61
=> x = 13
c. 124+(118-x)=217
=> 118-x=217-124
=> 118-x=93
=> x = 118-93
=> x = 25
Vận dụng điều lưu ý trong phần tóm tắt kiến thức.
a) Nếu (x - 35) - 120 = 0 thì x - 35 = 120. Do đó x = 120 + 35 = 155.
b) Nếu 124 + (118 - x) = 217 thì 118 - x = 217 - 124 hay 118 - x = 93.
Do đó x = 118 - 93 = 25.
c) 156 - (x + 61) = 82 suy ra x + 61 = 156 - 82 hay x + 61 = 74.
Do đó x = 74 - 61 = 13.
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a) 70 - 5 .(x -3 ) =45
b) 156 - ( x + 61 )+82
c) 10 +2 .x = 4 mũ 5 : 4 mũ 3
d) [(10 - x ).2 +3 ];3 -2=13
a) 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
b) 156 - ( x + 61 )+82
sai đề ( không có kết quả )
c) 10 +2 .x = 45 : 43
10 + 2 . x = 42 = 16
2 . x = 16 -10
2 . x = 6
x = 6 : 2
x = 3
d) [(10 - x ).2 +3 ];3 -2=13
[ ( 10 - x ) . 2 + 3 ] : 3 = 13 + 2
[ ( 10 - x ) . 2 + 3 ] : 3 = 15
[ ( 10 - x ) . 2 + 3 ] = 15 x 3
[ ( 10 - x ) . 2 + 3 ] = 45
( 10 - x ) . 2 = 45 - 3
( 10 - x ) . 2 = 42
10 - x = 42 : 2
10 - x = 21
x = 10 - 21
x = - 11
hok tốt
\(70-5\left(x-3\right)=45\)
\(5\left(x-3\right)=70-45\)
\(5\left(x-3\right)=25\)
\(x-3=\frac{25}{5}=5\)
\(x=5+3\)
\(x=8\)
\(10+2x=\frac{4^5}{4^3}\)
\(10+2x=4^2=16\)
\(2x=16-10\)
\(2x=6\)
\(x=\frac{6}{2}=3\)
Tim x € N biet :
a / x + 16 = 25
b / 156 - 2x = 82
c / 150 -150 : ( 18 - x ) = 125
d / 62 : x = 23 - 4
e / x + 3x + 5x + ................. +99x = 75 × 102
a) x = 25 - 16
x = 9
b) 2x = 156-82
2x = 74
x = 74 : 2
x = 37
c) 150 : (18-x) = 150-125
150 : (18-x) = 25
18-x = 150 : 25
18-x = 6
x =18-6
x= 12
d) 6.6 :x = 8-4
36 : x = 4
x =36:4
x = 9
e)(99x-x) : 2+1= 50x
Ta có:
50x + (1+3+5+7+9+.....+99)=75.10.10
50x + (99+1).50:2 =7500
50x + 2500=7500
50x=7500-2500
50x=5000
x =5000:50
x = 100
Tim x € N biet :
a / x + 16 = 25
=> x = 25 - 16
=> x = 9
b / 156 - 2x = 82
=> 2x = 156 - 82
=> 2x = 74
=> x = 37
c / 150 -150 : ( 18 - x ) = 125
=> 150 : ( 18 - x ) = 125 -150
=> 150 : ( 18 - x ) = - 25
=> 18 - x = -6
=> x = 18 - ( -6 )
=> x = 24
d / 62 : x = 23 - 4
=> 36 : x = 8 - 4
=> 36 : x = 4
=> x = 36 : 4
=> x = 9
e / x + 3x + 5x + ................. +99x = 75 × 102
=> x + 3x + 5x +....+ 99x = 7500
=> x. ( 1 + 3 + 5 +....+ 99 ) = 7500
Số các số hạng là : ( 99 - 1 ) : 2 + 1 = 50
=> Số cặp là : 50 : 2 = 25
Ta có:
x. ( 1 + 3 + 5 +....+ 99 ) = 7500
=> x. [ ( 1 + 99 ) + ( 2 + 98 ) +.... ] = 7500
=> x. 100 .25 =7500
=> x. 2500 = 7500
=> x = 7500 : 2500
=> x = 3
a) x = 25 - 16
x = 9
b) 2x = 156-82
2x = 74
x = 74 : 2
x = 37
c) 150 : (18-x) = 150-125
150 : (18-x) = 25
18-x = 150 : 25
18-x = 6
x =18-6
x= 12
d) 6.6 :x = 8-4
36 : x = 4
x =36:4
x = 9
e)(99x-x) : 2+1= 50x
Ta có:
50x + (1+3+5+7+9+.....+99)=75.10.10
50x + (99+1).50:2 =7500
50x + 2500=7500
50x=7500-2500
50x=5000
x =5000:50
x = 100
1.Tìm số tự nhiên x biết 1) (x-35) -120=0 2) 310-(118-x) =217 3) 156-(x+61)=82 4) 814-(x-305)=712 5) 100-7-(x-5)=58 6) 12(x-1):3=4^3+2^3 7) 24+5x=7^5:7^3 8) 5.(x-1) :3=4^3+2^3 9) 5(x-4)^2-7=13 10) (x+1)+(x+2)+....(x+30)=795 Giúp em với Mai em đi học rồi Help
1) (x - 35) - 120 = 0
x - 35 = 120
x = 120 + 35
x = 155
2) 310 - (118 - x) = 217
118 - x = 310 - 217
118 - x = 93
x = 118 - 93
x = 25
3) 156 - (x + 61) = 82
x + 61 = 156 - 82
x + 61 = 74
x = 74 - 61
x = 13
4) 814 - (x - 305) = 712
x - 305 = 814 - 712
x - 305 = 102
x = 102 + 305 = 407
5) 100 - 7 - (x - 5) = 58
x - 5 = 93 - 58
x - 5 = 35
x = 35 + 5 = 40
6) 12(x - 1) : 3 = 43 + 23
4(x - 1) = 72
x - 1 = 18
x = 18 + 1 = 19
7) 24 + 5x = 75 : 73
24 + 5x = 49
5x = 25
x = 25 : 5 = 5
8) 5(x - 1) : 3 = 43 + 23
\(\dfrac{5}{3}\left(x-1\right)=72\)
x - 1 = \(\dfrac{216}{5}\)
x = 221/5
9) 5(x - 4)2 - 7 = 13
5(x - 4)2 = 20
(x - 4)2 = 4
\(\Rightarrow\left[{}\begin{matrix}x-4=2\\x-4=-2\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}x=6\\x=2\end{matrix}\right.\)
10) (x + 1) + (x + 2) + ... + (x + 30) = 795
=> (x + x + x + ... + x) + (1 + 2 + 3 +...+ 30) = 795 (1)
Đặt A = 1 + 2 + 3 +...+ 30
Số số hạng trong A là: (30 - 1) : 1 + 1 = 30 (số)
Tổng A bằng : (30 + 1).30 : 2 =465
Thay A = 465 vào (1) , ta được:
30x + 465 = 795
=> 30x =330
=> x =11
1: =>x-35=120
=>x=120+35=155
2: =>118-x=310-217=93
=>x=118-93=25
3: =>x+61=156-82=74
=>x=74-61=13
4: =>x-305=814-712=102
=>x=102+305=407
5: =>93-(x-5)=58
=>x-5=35
=>x=40
6: =>4(x-1)=64+8=72
=>x-1=18
=>x=19
7: =>5x+24=49
=>5x=25
=>x=5
8: =>5(x-1):3=4^3+2^3=64+8=72
=>5(x-1)=216
=>x-1=216/5
=>x=221/5
bài 1 tìm x
a/ [x -35]-120=0
b/124+[118-x]=217
c/ 156-[x+61]=82
a)
(x-35)-120=0
=>x-35=0+120
=>x-35=120
=>x=120-35
=>x=85
b)
124+(118-x)=217
=>118-x=217-124
=>118-x=93
=>x=118-93
=>x=25
c) 125-(x+61)=82
=>x+61=125-82
=>x+61=43
=>x= 43-61
=>x= -18
a)
(x-35)-120=0
=>x-35=0+120
=>x-35=120
=>x=120-35
=>x=85
b)
124+(118-x)=217
=>118-x=217-124
=>118-x=93
=>x=118-93
=>x=25
c) 125-(x+61)=82
=>x+61=125-82
=>x+61=43
=>x= 43-61
=>x= -18
a)
(x-35)-120=0
=>x-35=0+120
=>x-35=120
=>x=120-35
=>x=85
b)
124+(118-x)=217
=>118-x=217-124
=>118-x=93
=>x=118-93
=>x=25
c) 125-(x+61)=82
=>x+61=125-82
=>x+61=43
=>x= 43-61
=>x= -18
Tim so nguyen x biet:
a,x-(-24)=3
b,(x+5)-(x-9)=x+3
c,c(x+2)=0
d,(x-1)^2=0
e,x^2-3x=0
f,-13-(6-|x+1|)=24
g,26-|x+9|=-13
i,(3x-6).3=3^4