-(x+81)=(2x+12)-(5+x)
353-x=46+(3x-21)
tìm số nguyên x, biết:
a) 353-x=46+(3x-21)
b) -(x+81)=(2x+12)-(5+x)
c)-x+821+534=499+(x-84)
d) x+53=(400-9x)-447
Tìm số nguyên x, biết:
a) 353-x=46+(3x-21). b) -(x+81)=(2x+12)-(5+x).
c) (-x+821+534)=499+(x-84). d) x+53=(400-9x)-447.
\(a,353-x=46+\left(3x-21\right)\)
\(353-x=138x-25\)
\(-x-138x=-25-353\)
\(-139x=-378\Leftrightarrow x=\frac{378}{139}\)
\(b,-\left(x+81\right)=\left(2x+12\right)-\left(5+x\right)\)
\(-x-81=2x+12-5-x\)
\(-x+x-2x=12-5+81\)
\(-2x=88\Leftrightarrow x=-44\)
Tìm số nguyên x biết:
a) x-96=(443-x)-15
b) (x-12)-15=(20-7)-(18-x)
c) 353-x=46+(3x-21)
d) -(x+81)=(2x+12)-(5+x)
e) (-x+821+534)=499+(x-84)
g) x+53= (400-9x)-447
a, x - 96 = ( 443 - x ) - 15
x - 96 = 443 - x - 15
x - 96 = 428 - x
x + x = 428 + 96
2x = 524
x = 262
b, ( x - 12 ) - 15 = ( 20 - 7 ) - ( 18 - x )
x - 12 - 15 = 13 - 18 + x
x - 27 = - 5 + x
x - x = - 5 + 27
0x = 22
=> ko có giá trị nào thõa mãn
c, 353 - x = 46 + ( 3x - 21 )
353 - x = 46 + 3x - 21
353 - x = 25 + 3x
- x - 3x = 25 - 353
- 4x = - 328
x = 82
d, - ( x + 81 ) = ( 2x +12 ) - ( 5 + x )
- x - 81 = 2x + 12 - 5 - x
- x - 81 = x + 7
- x - x = 7 + 81
- 2x = 88
x = - 44
e, ( - x + 821 + 534 ) = 499 + ( x - 84 )
- x + 1355 = 499 + x - 84
- x - x = 499 - 84 - 1355
- 2x = - 940
x = 470
g, x + 53 = ( 400 - 9x ) - 447
x + 53 = 400 - 9x - 447
x + 53 = - 47 - 9x
x + 9x = - 47 - 53
10x = -100
x = - 10
Mấy bạn giúp mình vs:
353 - x = 46 + ( 3x - 21 )
353 - x = 46 + (3x - 21)
\(\Leftrightarrow\)353 - x = 3x + 25
\(\Leftrightarrow\)3x + x = 353 - 25
\(\Leftrightarrow\)4x = 328
\(\Leftrightarrow\)x = 328 : 4 = 82
Vậy x = 82
Bạn tìm Mẫu Thức Chung
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Kết Luận
\(\frac{x+3}{12}+\frac{2x+46}{16}=\frac{3x+9}{36}+\frac{5x+81}{6}\Leftrightarrow\frac{2\left(x+3\right)}{24}+\frac{\frac{3}{2}\left(2x+46\right)}{\frac{3}{2}.16}=\frac{\frac{2}{3}\left(3x+9\right)}{\frac{2}{3}.36}+\frac{4\left(5x+81\right)}{4.6}\)
\(\Leftrightarrow\frac{2\left(x+3\right)}{24}+\frac{3x+69}{24}=\frac{2x+6}{24}+\frac{20x+324}{24}\)\(\Leftrightarrow2x+6+3x+69=2x+6+20x+324\Leftrightarrow17x=-255\Leftrightarrow x=-\frac{255}{17}\)Vậy \(x=-\frac{255}{17}\)
Bài 4: Tìm số nguyên x biết
a, 2x .7 = 224 b, x10 = x c, ( 2x + 1)3 = 125 d, ( x-5)4= (x - 5)6
e) |2x - 5| - 1 = 12 g) 353 – x = 46 + (3x + 21)
a, 2x . 7 =224
<=>2x = 224 : 7
<=> 2x=32
<=> 2x=25 => x = 5
Vaậy x = 5
b, x10=x
<=> x 10 - x =0
<=> x . ( x9 - 1 ) = 0
<=> \(\orbr{\begin{cases}x=0\\x^9-1=0\end{cases}\Rightarrow\orbr{\begin{cases}x=0\\x=1\end{cases}}}\)
Vậy x = 0 hoặc x = 1
c, ( 2.x + 1 ) 3 = 125
<=> (2.x + 1 ) 3 = 53
<=> 2.x+1 = 5
<=> 2.x = 4
<=> x = 2
Vậy x = 2
.
Bài 4: Tìm số nguyên x biết
a, 2x .7 = 224
2x=224:7
2x=32
2x=25
x=5
Vậy x=5
b, x10 = x
vô lí vì 10 ko bằng 1
Vậy x EO
c, ( 2x + 1)3 = 125
(2x+1)3=53
2x+1=5
2x=5-1
2x=4
x=4:2
x=2
Vậy x=2
d, ( x-5)4= (x - 5)6
(x-5)4-(x-5)6=0
(x-5)4.[1-(x-5)2 ]=0
* (x-5)4=0 * 1-(x-5)2=0
x-5=0 (x-5)2=1
x=5 * x-5=1 * x-5=-1
x=6 x=4
vậy.............................................................................
e) |2x - 5| - 1 = 12
|2x-5|=13
\(\Rightarrow\orbr{\begin{cases}2x-5=13\\2x-5=-13\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=9\\x=-4\end{cases}}\)
Vậy,,,,,,,,,,,,,,,,,,,,,,,,,,,,
g) 353 – x = 46 + (3x + 21)
353-x=46+3x+21
353-46-21=3x+x
286=4x
x=286:4
x=71,5
A) 78-2x=42
B)6x+39=75
C) 2^3.x+ 2.x=25.2^2
D) 21+7x = 56
E) 5x +2x = 6^2-5^0
F)15x + 3x = 450 : 2+9
G) 6x+x=5^11: 5^9+3^1
H) 5x + 3x=3^11: 3^8.4+12
i) 2^3.x + 2^2.x =136-2^20 : 2^16
j) 7x -x= 5^21: 5^19+3.2^2
k) 7x - 2x= 6^17: 6^15 + 44 :11
l) 0: x =0 m) 3^x=27 n) 4^x= 64
o) 2^x = 32 p) 9^x-1=81 q) x^4=16
r) 3^x :3^
p) 9^x-1=81
q) x^4=165=1
CÁC BN BIẾT ANH Meowpeo và chị Simmy, Kamui và Naobi Chan , Sammy không
Mình fan của họ
Nếu có , cho mình và kết bạn với mình nhé!
TYM TYM
Các bn ơi giúp mình câu này đc ko mong các bạn giúp đỡ 4(x-1)=2x-6(x-2) các bạn giải hộ mình với
Giải các phương trình sau:
1/(x+2)(x+3)(x-7)(x-8)=144
2/ (6x+5)^2(3x+2)(x+1)=35
3/ (x-4)(x - 5)(x-8)(x-10) = 72^2
4/ (x+10)(x+12)(x+15)(x+18) =2x^2
Mong mọi người giúp đỡ ạ (´ε` )(。’▽’。)♡
`1)(x+2)(x+3)(x-7)(x-8)=144`
`<=>[(x+2)(x-7)][(x+3)(x-8)]=144`
`<=>(x^2-5x-14)(x^2-5x-24)=144`
`<=>(x^2-5x-19)^2-25=144`
`<=>(x^2-5x-19)^2-169=0`
`<=>(x^2-5x-6)(x^2-5x-32)=0`
`+)x^2-5x-6=0`
`<=>` $\left[ \begin{array}{l}x=6\\x=-1\end{array} \right.$
`+)x^2-5x-32=0`
`<=>` $\left[ \begin{array}{l}x=\dfrac{5+3\sqrt{17}}{2}\\x=\dfrac{5-3\sqrt{17}}{2}\end{array} \right.$
Vậy `S={-1,6,\frac{5+3\sqrt{17}}{2},\frac{5-3\sqrt{17}}{2}}`
1: Ta có: \(\left(x+2\right)\left(x+3\right)\left(x-7\right)\left(x-8\right)=144\)
\(\Leftrightarrow\left(x^2-7x+2x-14\right)\left(x^2-8x+3x-24\right)=144\)
\(\Leftrightarrow\left(x^2-5x-14\right)\left(x^2-5x-24\right)-144=0\)
\(\Leftrightarrow\left(x^2-5x\right)^2-38\left(x^2-5x\right)+336-144=0\)
\(\Leftrightarrow\left(x^2-5x\right)^2-38\left(x^2-5x\right)+192=0\)
\(\Leftrightarrow\left(x^2-5x\right)^2-6\left(x^2-5x\right)-32\left(x^2-5x\right)+192=0\)
\(\Leftrightarrow\left(x^2-5x\right)\left(x^2-5x-6\right)-32\left(x^2-5x-6\right)=0\)
\(\Leftrightarrow\left(x^2-5x-6\right)\left(x^2-5x-32\right)=0\)
\(\Leftrightarrow\left(x-6\right)\left(x+1\right)\left(x^2-5x-32\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x-6=0\\x+1=0\\x^2-5x-32=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=6\\x=-1\\x=\dfrac{5-3\sqrt{17}}{2}\\x=\dfrac{5+3\sqrt{17}}{2}\end{matrix}\right.\)
Vậy: \(S=\left\{6;-1;\dfrac{5-3\sqrt{17}}{2};\dfrac{5+3\sqrt{17}}{2}\right\}\)
`2)(6x+5)^2(3x+2)(x+1)=35`
`<=>12(6x+5)^2(3x+2)(x+1)=420`
`<=>(6x+5)^2+(6x+4)(6x+6)=420`
Đặt `6x+5=a`
`pt<=>a^2(a+1)(a-1)=420`
`<=>a^2(a^2-1)-420=0`
`<=>a^4-a^2-420=0`
`<=>` $\left[ \begin{array}{l}a^2=-20(False)\\a^2=21(True)\end{array} \right.$
`<=>` $\left[ \begin{array}{l}a=\sqrt{20}\\a=-\sqrt{20}\end{array} \right.$
`<=>` $\left[ \begin{array}{l}6x+5=\sqrt{20}\\6x+5=-\sqrt{20}\end{array} \right.$
`<=>` $\left[ \begin{array}{l}x=\dfrac{\sqrt{20}-5}{6}\\x=\dfrac{-\sqrt{20}-5}{6}\end{array} \right.$
Vậy `S={\frac{\sqrt{20}-5}{6},\frac{-\sqrt{20}-5}{6}}`
đọc cách lm trrong sbt nha bạn lớp 8
mk học lớp 6 lên 7