Tìm x
x+2x+3x+4x+....+10x=385
Những câu hỏi liên quan
a, làm tính chia: (x^6-2x^5+2x^4+6x^3-4x^2)/6x^2
b,tìm n để đa thức 3x^3+10x^2-5+n chia hết cho đa thức 3x+1
: Tìm x, biết:
a) 3x( 4x- 1) - 2x(6x- 3 )30 b) 2x(3-2x) + 2x(2x-1)15
c) (5x-2)(4x-1) + (10x +3)(2x - 1)1 d) (x+2) (x+2)- (x -3)(x+1) 9
e) (4x+1)(6x-3) 7 + (3x – 2)(8x + 9) g) (10x+2)(4x- 1)- (8x -3)(5x+2) 14
Đọc tiếp
: Tìm x, biết:
a) 3x( 4x- 1) - 2x(6x- 3 )=30 b) 2x(3-2x) + 2x(2x-1)=15
c) (5x-2)(4x-1) + (10x +3)(2x - 1)=1 d) (x+2) (x+2)- (x -3)(x+1) = 9
e) (4x+1)(6x-3) = 7 + (3x – 2)(8x + 9) g) (10x+2)(4x- 1)- (8x -3)(5x+2) =14
`@` `\text {Ans}`
`\downarrow`
`a)`
`3x(4x-1) - 2x(6x-3) = 30`
`=> 12x^2 - 3x - 12x^2 + 6x = 30`
`=> 3x = 30`
`=> x = 30 \div 3`
`=> x=10`
Vậy, `x=10`
`b)`
`2x(3-2x) + 2x(2x-1) = 15`
`=> 6x- 4x^2 + 4x^2 - 2x = 15`
`=> 4x = 15`
`=> x = 15/4`
Vậy, `x=15/4`
`c)`
`(5x-2)(4x-1) + (10x+3)(2x-1) = 1`
`=> 5x(4x-1) - 2(4x-1) + 10x(2x-1) + 3(2x-1)=1`
`=> 20x^2-5x - 8x + 2 + 20x^2 - 10x +6x - 3 =1`
`=> 40x^2 -17x - 1 = 1`
`d)`
`(x+2)(x+2)-(x-3)(x+1)=9`
`=> x^2 + 2x + 2x + 4 - x^2 - x + 3x + 3=9`
`=> 6x + 7 =9`
`=> 6x = 2`
`=> x=2/6 =1/3`
Vậy, `x=1/3`
`e)`
`(4x+1)(6x-3) = 7 + (3x-2)(8x+9)`
`=> 24x^2 - 12x + 6x - 3 = 7 + (3x-2)(8x+9)`
`=> 24x^2 - 12x + 6x - 3 = 7 + 24x^2 +11x - 18`
`=> 24x^2 - 6x - 3 = 24x^2 + 18x -11`
`=> 24x^2 - 6x - 3 - 24x^2 + 18x + 11 = 0`
`=> 12x +8 = 0`
`=> 12x = -8`
`=> x= -8/12 = -2/3`
Vậy, `x=-2/3`
`g)`
`(10x+2)(4x- 1)- (8x -3)(5x+2) =14`
`=> 40x^2 - 10x + 8x - 2 - 40x^2 - 16x + 15x + 6 = 14`
`=> -3x + 4 =14`
`=> -3x = 10`
`=> x= - 10/3`
Vậy, `x=-10/3`
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(2x+3)/(4x+5)=(5x+2)/(10x+2)
tìm x
\(\frac{2x+3}{4x+5}=\frac{5x+2}{10x+2}\)
\(\Rightarrow\left(2x+3\right)\left(10x+2\right)=\left(5x+2\right)\left(4x+5\right)\)
\(\Rightarrow20x^2+4x+30x+6=20x^2+25x+8x+10\)
\(\Rightarrow x=4\)
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1)6x-8=3x+1
2)12-10x=25-30x
3)3(2x+3)-2(4x-5)=10x+21
4)5(5x-3)-3(2x-4)11-5x
5)4(2-3x)-5(1-2x)=4-6x
6)8(4x-3)-3(2-3x)=13-40x
7)10x-5(1-4x)=5x-11
8)-3(3-4x)-5(4-3x)=12x-50
9)-2(20x-3)-3(4x-5)=9-2(2x-3)
10)-5(2-3x)+3(5-2x)=3x+3(3-5x)
1)6x-8=3x+1
6x-3x=1+8
3x=9
x=3
Vậy x=3
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2: 12-10x=25-30x
=>20x=13
=>x=13/20
3: \(3\left(2x+3\right)-2\left(4x-5\right)=10x+21\)
=>6x+9-8x+10=10x+21
=>10x+21=-2x+19
=>12x=-2
=>x=-1/6
4: \(\Leftrightarrow25x-15-6x+12=11-5x\)
=>19x-3=11-5x
=>24x=14
=>x=7/12
5: \(\Leftrightarrow8-12x-5+10x=4-6x\)
=>4-6x=-2x+3
=>-4x=-1
=>x=1/4
6: \(\Leftrightarrow32x-24-6+9x=13-40x\)
=>41x-30=13-40x
=>81x=43
=>x=43/81
7: \(\Leftrightarrow10x-5+20x=5x-11\)
=>30x-5=5x-11
=>25x=-6
=>x=-6/25
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C1.10x2=6x+8
C2.23x+10=23+13x
C3.9x-6=4x+1
C4.15x-12=11x+15
C5.21x+9=19-11x
C6.15+16x=8-3x
C7.19-4x=8x+23
C8.51-10x=3x-21
C9.8-6x=11-4x
C10.2(3x+4)-3(1-2x)=8x+10
C11.5(3-4x)-4(2x-5)=9-10x
C12.3(5x-6)-2(2x-5)=11x-10
C13.10x+5(3x-2)=25-10x
C14.6(2x-3)+3(3-5x)=8x-9
C15.3(4x-2)+2(6-2x)=10-6x
C16.5(3-6x)-4(2-2x)=4x-9
B2:tìm cặp số nguyên x, y thỏa mãn
X y+2x+y=0
nhiều quá bạn ơi , mk nghĩ bạn nên tách ra rồi hãy đăng lên
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Bài 1:
16:
=>15-30x-8+8x=4x-9
=>-22x+7=4x-9
=>-26x=-16
=>x=8/13
15: \(\Leftrightarrow12x-6+12-4x=10-6x\)
=>8x+6=10-6x
=>14x=4
=>x=2/7
14: \(\Leftrightarrow12x-18+9-15x=8x-9\)
=>-3x-9=8x-9
=>x=0
13: \(\Leftrightarrow10x+15x-10=25-10x\)
=>25x-10=25-10x
=>35x=35
=>x=1
12: \(\Leftrightarrow15x-18-4x+10=11x-10\)
=>11x-8=11x-10(loại)
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Xem thêm câu trả lời
Tìm x:
a.12x^2-4x(3x-5)=10x-17
b.1/5x.(10x-15)-2x(x-5)=12
c.3x(4/3x+1)-4x(x-2)=10
2.tính gtbt
A=5-4x(x-2)+4x^2 tại x=4
làm khuyến mại 1 câu;
a) = 12x2 -12x2 +20x -10x +17 =0
10x = -17
x = -17/10
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x/2 - ( 3x/5 - 13/5 ) = -( 7/5 + 7/10x )
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a) = 12x2 -12x2 +20x -10x +17 =0
10x = -17
x = -17/10
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làm phép chia
1) (x^6 - 2x^4 + 6x^3 - 4x^2) : 6x^2
2) (-2x^5 = 3x^2 - 4x^3) : 2x^2
3) (15x^3 - 10x^2 + x - 2) : (x - 2)
4) (2x^4 -3x^3 - 3x^2 + 6x - 2) : (x^2 - 2)
2x+3/3x+2=4x+5/10x+2
\(\frac{2x+3}{3x+2}=\frac{4x+5}{10x+2}\)
\(\Leftrightarrow\left(2x+3\right)\left(10x+2\right)=\left(3x+2\right)\left(4x+5\right)\)
\(\Leftrightarrow20x^2+34x+6=12x^2+23x+10\)
\(\Leftrightarrow8x^2+11x-4=0\)
Ta có: \(\Delta=11^2+4.4.8=249,\sqrt{\Delta}=\sqrt{249}\)
Vậy pt có 2 nghiệm:
\(x_1=\frac{-11+\sqrt{249}}{16}\);\(x_2=\frac{-11-\sqrt{249}}{16}\)
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x+2x+3x+3x+4x+5x+6x+7x+8x+9x+10x=-165.tim x
X*(1+2+3+4+5+6+7+8+9+10)=-165
X*55=-165
X=-165/55=-3
111111111111111111111111111111111111111111111111111111111111111111111111111111111111111
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(1x + 9x) + (2x + 8x) + (3x + 7x) + (4x + 6x) + 5x + 10x = -165
10x^6 + 5x = -165
= 65x (-165)
= -100
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