Tìm x biết 5x^2+8x-4=0
tìm x biết x^3+5x^2+8x+4=0
x^3+5x^2+8x+4=0
x^3+x^2+4x^2+4x+4x+4=0
x^2(x+1)+4x(x+1)+4(x+1)=0
(x+1)(x^2+4x+4)=0
x+1=0 =>x=-1
x^2+4x+4=0
x^2+2x+2x+4=0
x(x+2)+2(x+2)=0
(x+2)^2=0
x=-2
Vậy x=-2,x=-1
Tìm x,biết
a) x^3-5x^2+8x-4=0
b)x^5-x^3-x^2+1=0
x^5 -x^3 -x^2 +1=0
x^3(x^2 -1 )-(x^2-1)=0
(x-1)(x^2+x+1)(x-1)(x+1)=0
(x-1)^2(x+1)(x^2+x+1)=0
=> x=1;x=-1
x^3- 5x^2+ 8x- 4= x^3- x^2- 4x^2+ 4x+ 4x- 4
= x^2(x-1)- 4x(x-1)+4(x-1)
= (x-1)(x^2-4x+4)
= (x-1)(x-1)^2
=(x-1)^3
Tìm x biết
a) 4(x-1)×(x+5)-(x+2)×(x+5)=3×(x-1)×(x+2)
b) x^3-5x^2+8x-4=0\
Tìm x, biết
1)x3-5x2+8x-4=0
2)2x3-x2+3x+6=0
1,
<=> \(\left(x-1\right)\left(x-2\right)^2=0\)
=> x=1 hoặc x=2
2,
<=>\(\left(x+1\right)\left(2x^2-3x+6\right)\)=0
=> x=-1
1.
<=> ( x -1 ) ( x - 2 ) 2 = 0
=> x = 1 hoặc x = 2
2.
<=> ( x + 1 ) ( 2x2 - 3x + 6 ) = 0
=> x = -1
tìm x biết:
5x^2+(-8x)=0
x=0
#Tự_tìm_lời_giải_nha_NGẠI_GHI
#Hk_tốt
#Ngọc's_Ken
\(5x^2+\left(-8x\right)=0\)
\(\Rightarrow5x^2-8x=0\)
\(\Rightarrow x\left(5x-8\right)=0\)
Từ đó ta xét 2 trường hợp :
TH1 :\(x=0\)
TH2 : \(5x-8=0\)
\(\Rightarrow5x=8\)\(\Rightarrow x=\frac{8}{5}\)
\(\Rightarrow x\in\left\{0;\frac{8}{5}\right\}\)
5x2 + (-8x) = 0
=> 5x2 - 8x = 0
=> x(5x - 8) =0
=> \(\orbr{\begin{cases}x=0\\5x-8=0\end{cases}}\)
=> \(\orbr{\begin{cases}x=0\\5x=8\end{cases}}\)
=> \(\orbr{\begin{cases}x=0\\x=\frac{8}{5}\end{cases}}\)
Vậy x=0 hoặc x=\(\frac{8}{5}\)
Tìm x,biết
a) ( x+2)×(x+3)-(x -2)×(x+5)=0
b) (2x+3)×(x-4)+(x-5)×(x-2)=(3x-5)×(x-4)
c) (8-5x)×(x+2)+4(x-2)×(x+1)+2(x-2)×(x+2)=0
d) (8x-3)×(3x+2)-(4x+7)×(x+4)=(2x+1)×(5x-1)-33
Tìm x, biết:
6) x^3 - 2x^2 + 2x = 0
7) 2x^3 - 5x^2 + 8x - 5 = 0
bài 1 :tìm x,y biết
a) (5x+1)=\(\dfrac{36}{49}\) b) (x-2/9) = (2/3) c)(8x-1) 2x+1= 5^2 x+1
d) (x-3,5)^x+(y - 1/10)^4=0
`(5x+1)=36/49`
`<=> 5x = 36/49-1`
`<=> 5x = -13/49`.
`<=> x = -13/245.`
Vậy `x = -13/245`.
`b, x-2/9 = 2/3`.
`<=> x = 2/3 + 2/9`
`<=> x = 8/9`.
Vậy `x = 8/9`.
c: (8x-1)^(2x+1)=5^(2x+1)
=>8x-1=5
=>8x=6
=>x=3/4
d: Sửa đề: (x-3,5)^2+(y-1/10)^4=0
=>x-3,5=0 và y-0,1=0
=>x=3,5 và y=0,1
Tìm x biết.
a) 4x^2 - 49 = 0 b) x^2 + 36 = 12x
c) 1/16x^2 - x + 4 = 0 d) x^3 -3√3x2 + 9x - 3√3 = 0
e) (x - 2)^2 - 16 = 0 f) x^2 - 5x - 14 = 0
g) 8x(x - 3) + x - 3 = 0
a, 4x2 - 49 = 0
⇔⇔ (2x)2 - 72 = 0
⇔⇔ (2x - 7)(2x + 7) = 0
⇔{2x−7=02x+7=0⇔⎧⎪ ⎪⎨⎪ ⎪⎩x=72x=−72⇔{2x−7=02x+7=0⇔{x=72x=−72
b, x2 + 36 = 12x
⇔⇔ x2 + 36 - 12x = 0
⇔⇔ x2 - 2.x.6 + 62 = 0
⇔⇔ (x - 6)2 = 0
⇔⇔ x = 6
e, (x - 2)2 - 16 = 0
⇔⇔ (x - 2)2 - 42 = 0
⇔⇔ (x - 2 - 4)(x - 2 + 4) = 0
⇔⇔ (x - 6)(x + 2) = 0
⇔{x−6=0x+2=0⇔{x=6x=−2⇔{x−6=0x+2=0⇔{x=6x=−2
f, x2 - 5x -14 = 0
⇔⇔ x2 + 2x - 7x -14 = 0
⇔⇔ x(x + 2) - 7(x + 2) = 0
⇔⇔ (x + 2)(x - 7) = 0
⇔{x+2=0x−7=0⇔{x=−2x=7
a,\(4x^2-49=0\)
\(\Leftrightarrow\left(2x\right)^2-7^2=0\)
\(\Leftrightarrow\left(2x-7\right)\left(2x+7\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}2x-7=0\\2x+7=0\end{cases}\Leftrightarrow\orbr{\begin{cases}2x=7\\2x=-7\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=\frac{7}{2}\\x=-\frac{7}{2}\end{cases}}}\)
b.\(x^2+36=12x\)
\(\Leftrightarrow x^2-12x+36=0\)
\(\Leftrightarrow\left(x-6\right)^2=0\)
\(\Leftrightarrow x-6=0\Leftrightarrow x=6\)
c.\(\frac{1}{16x^2}-x+4=0\)
\(\Leftrightarrow\left(\frac{1}{4x}\right)^2-2.\frac{1}{4x}.2+2^2=0\)
\(\Leftrightarrow\left(\frac{1}{4x}-2\right)^2=0\)
........