thực hiện phép tính
a)120:{50.50:[450-(4.125-4.25 )]}
tìm x biết
a) (2.x-4).(48-12.x)=0
b)134-2.{156-6[54-2 .(9+6)]}.x=86
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134 - 2 . {156 - 6[54 - 2(9 + 6)]} . x = 86
134 - 2 . { 156 - 6 [ 54 - 2 . 15 ) ] } . x = 86
134 - 2 . { 156 - 6 [ 54 - 30 ] } . x = 86
134 - 2 . { 156 - 6 . 24 } . x = 86
134 - 2 . { 156 - 144 } . x = 86
134 - 2 . 21 . x = 86
2 . 21 . x = 134 - 86
2 . 21 . x = 48
21 . x = 48 : 2
21 . x = 24
x = 24 : 21
x = 1
a,\(\left(x-15\right):50+22=24\)
\(< =>\frac{\left(x-15\right)}{50}=2< =>x-15=100\)
\(< =>x=100+15=115\)
b,\(42-\left(2x+32\right)+12:2=6\)
\(< =>42-2x-32=0\)
\(< =>10-2x=0< =>x=\frac{10}{2}=5\)
Làm nốt :
c) \(134-2\left\{156-6\cdot\left[54-2\cdot\left(9+6\right)\right]\right\}\cdot x=86\)
=> 134 - 2{156 - 6 . [54 - 2 . 15]} . x = 86
=> 134 - 2{156 - 6 . [54 - 30]} . x = 86
=> 134 - 2{156 - 6. 24} . x = 86
=> 134 - 2{156 - 144} . x = 86
=> 134 - 2.12 . x = 86
=> 134 - 24 . x = 86
=> 24.x = 48
=> x = 2
Bài 2 : a) 120 : [21 - (4x - 4)] = 23.3
=> 120 : [21 - (4x - 4)] = 8.3
=> 120 : [21 - (4x - 4)] = 24
=> 21 - (4x - 4) = 5
=> 4x - 4 = 16
=> 4x = 20
=> x = 5
b) 3.[205 - (x - 9)] - 486 = 0
=> 3.[205 - (x - 9)] = 486
=> 205 - (x - 9) = 162
=> x - 9 = 205 - 162 = 43
=> x = 43 + 9 = 52
c) 204 - 2{200 - 5.[64 - 2.(11 + 6)]} . x = 4
=> 204 - 2{200 - 5.[64 - 2.17]} . x = 4
=> 204 - 2{200 - 5 .[64 - 34]}.x = 4
=> 204 - 2{200 - 5.30} . x = 4
=> 204 - 2{200 - 150}.x = 4
=> 204 - 2.50 . x = 4
=> 2.50.x = 200
=> 100.x = 200
=> x = 2
1)
a) \(=15x^3-20x^2+10x\)
b) \(=3x^4-x^3+4x^2-9x^3+3x-12x=3x^4-10x^3+4x^2-9x\)
2)
a) \(\Rightarrow x\left(x^2-6x+12\right)=0\)
\(\Rightarrow x=0\)(do \(x^2-6x+12=\left(x^2-6x+\dfrac{36}{4}\right)+3=\left(x-\dfrac{6}{2}\right)^2+3\ge3>0\))
b) \(\Rightarrow\left(x+3\right)^3=0\Rightarrow x=-3\)
(3x²-5x+2)+(3x²+5x)= bao nhiêu ạ
Giúp em vs ạ . Em cảm ơn
Bài 2:
a: =>x-1=1 hoặc x-1=-1
=>x=2 hoặc x=0
b: =>x+1=-1
hay x=-2
c: =>(135-7x):9=8
=>135-7x=72
=>7x=63
hay x=9
d: =>(x+7)(x-3)<0
=>-7<x<3
e: \(\Leftrightarrow3^{x-3}=18+9=27\)
=>x-3=3
hay x=6
f: =>4-2x=0
hay x=2
42 -(2x + 32) + 12 :2 =6
42 - 2x - 32 + 6 = 6
42 - 2x - 32 = 0
42 - 2x = 32
2x = 42 - 32 = 10
x = 5
134 - 2 . {156 - 6.[54 -2.(9+6) ] } x = 86
134 - 2.{ 156 - 6.[54 - 2 . 15 ]} x = 86
134 - 2.{ 156 - 6 . 24} x = 86
134 - 2. 12 .x = 86
134 - 24x = 86
24x = 48
x = 2
\(42-\left(2x+32\right)+12:2=6\)
\(\Rightarrow42-2x-32=0\)
\(\Rightarrow2x=10\)
\(\Rightarrow x=5\)
134 - 2.{ 156 - 6 .[ 54 - 2 .( 9 + 6 )]} . x = 86
134 - 2.{ 156 - 6 .[ 54 - 2 . 15 ]} . x = 86
134 - 2.{ 156 - 6 .[ 54 - 30 ]} . x= 86
134 - 2.{ 156 - 6 . 24 } . x = 86
134 - 2.{ 156 - 144 } . x = 86
134 - 2 . 12 . x = 86
134 - 24 . x = 86
24 . x = 134 - 86
24 . x = 48
x = 48 : 24
x = 2
134-2.{156-6.[54-2.(9+6)]}.x=86
2.{156-6.[54-2.15]}.x=134-86
2.{156-6.[54-30]}.x=48
2.{[156-6.24]}.x=48
2.{[156-144]}.x=48
2.{12}.x=48
24.x=48
x=48:24
x=2
Vậy x=2
Chúc bn học tốt
a) 120:{50.50:[450 - (4.125 - 4.25)]}
= 120:{50.50:[450 - (4.25.5 - 4.25)]}
= 120:{50.50:[450 - (4.25(5 - 1))]}
= 120:{50.50:[450 - (100.4)]}
= 120:{50.50:[450 - 400]}
= 120:{50.50:50}
= 120:50
= 12/5
a) (2x - 4)(48 - 12x) = 0
=> 2(x - 2).12(4 - x) = 0
=> (x - 2)(4 - x) = 0 (2 và 12 khác 0)
=> x - 2 = 0 hay 4 - x = 0
=> x = 2 I => x = 4
b) 134 - 2{156 - 6[54 - 2(9 + 6)]}x = 86
=> 134 - 2{156 - 6[54 - 2.15]}x = 86
=> 134 - 2{156 - 6[54 - 30]}x = 86
=> 134 - 2{156 - 6.24}x = 86
=> 134 - 2{12.13 - 12.2.6}x = 86
=> 134 - 2{12[13 - 2.6]}x = 86
=> 134 - 2{12[13 - 12]}x = 86
=> 134 - 2{12.1}x = 86
=> 134 - 2.12x = 86
=> 134 - 24x = 86
=> 24x = 48
=> x = 2