tim x biet
16x^3 - 12x^2 + 3x - 7 = 0
Tìm x, biết: \(16x^3-12x^2+3x-7=0\)
\(16x^3-12x^2+3x-7=0\)
\(\Leftrightarrow16x^3-16x^2-3x^2+3x+7x^2-7=0\)
\(\Leftrightarrow16x^2\left(x-1\right)-3x\left(x-1\right)+7\left(x-1\right)\left(x+1\right)=0\)
\(\Leftrightarrow16x^2\left(x-1\right)-3x\left(x-1\right)+\left(x-1\right)\left(7x+7\right)=0\)
\(\Leftrightarrow\left(x-1\right)\left(16x^2-3x+7x+7\right)=0\)
\(\Leftrightarrow\left(x-1\right)\left(16x^2+4x+7\right)=0\)
<=> x - 1 = 0
<=> x = 1
\(\Leftrightarrow16x^3-16x^2+4x^2-4x+7x-7=0\)
\(\Leftrightarrow16x^2.\left(x-1\right)+4x.\left(x-1\right)+7.\left(x-1\right)=0\)
\(\Leftrightarrow\left(x-1\right).\left(16x^2+4x+7\right)=0\)
Ta có \(16x^2+4x+7=\left(4x\right)^2+2.4x.\frac{1}{2}+\frac{1}{4}+\frac{27}{4}\)
\(=\left(4x+\frac{1}{2}\right)^2+\frac{27}{4}>0\)
nên \(\left(x-1\right).\left(16x^2+4x+7\right)=0\)
\(\Leftrightarrow x-1=0\)
\(\Rightarrow x=1\)
tìm X biết \(16X^3-12X^2+3X-7=0\)
\(16x^3-12x^2+3x-7=0\)
\(16x^3-16x^2+4x^2-4x+7x-7=0\)
\(16x^2\left(x-1\right)+4x\left(x-1\right)+7\left(x-1\right)=0\)
\(\left(x-1\right)\left(16x^2+4x+7\right)=0\)
Vì \(0< 16x^2+4x+7\)
\(\Rightarrow x-1=0\)
\(\Rightarrow x=1\)
Tìm x, biết 16x3 - 12x2 + 3x - 7 = 0
= 16x3 -16x2 + 4x2 - 4x + 7x - 7
= 16x2(x-1)+4x(x-1)+7(x-1)
=(x-1)(16x2+4x+7)
Giúp mình giải bài tìm x
16x^3 - 12x^2 + 3x - 7 = 0
16x^3 - 12x^2 + 3x - 7 = 0
=>16x3+4x2-16x2+7x-4x-7=0
=>16x3+4x2+7x-16x2-4x-7=0
=>x(16x2+4x+7)-(16x2+4x+7)=0
=>(x-1)(16x2+4x+7)=0
=>x-1=0 hoặc 16x2+4x+7=0
Với x-1=0 =>x=1Với 16x2+4x+7=0\(\Rightarrow16\left(x+\frac{1}{8}\right)^2+\frac{27}{4}>0\) với mọi x =>vô nghiệm
Vậy phương trình trên có nghiện thỏa mãn là x=1
tim x pik
(12x-5)*(4X-1)+(3X-7)*(1-16X)=81
(12x-5)(4x-1)+(3x-7)(1-16x)=81
tim x do ....giup minh vs
1) x(x-3)-2x(x-3)=0
2) x(3x-1)-5(1-3x)=0
3) 5(x+3)-2x(3x+3)=0
4) 4x(x+3)-x-3=0
5) x3+15x2+75x+125=0
6) 4x2-12x+9=0
7) x2-16x+60=0
8) x3+48x=12x2+64
1,=\(x^2-3x-2x^2+6x=-x^2+3x\)
2,=\(3x^2-x-5+15x=3x^2+14x-5\)
3,=\(5x+15-6x^2-6x=-6x^2-x+15\)
4,=\(4x^2+12x-x-3=4x^2+11x-3\)
5: =>(x+5)^3=0
=>x+5=0
=>x=-5
6: =>(2x-3)^2=0
=>2x-3=0
=>x=3/2
7: =>(x-6)(x-10)=0
=>x=10 hoặc x=6
8: \(\Leftrightarrow x^3-12x^2+48x-64=0\)
=>(x-4)^3=0
=>x-4=0
=>x=4
Tìm x, biết:
a) (2x+2)(x-1)-(x+2)(2x+1)=0;
b)(3x+1)(2x-3)-6x(x+2)=16;
c)(12x-5)(4x-1)+(3x-7)(1-16x)=81
mn ơi giúp mik vs ạ :<
a: =>2x^2-2x+2x-2-2x^2-x-4x-2=0
=>-5x-4=0
=>x=-4/5
b: =>6x^2-9x+2x-3-6x^2-12x=16
=>-19x=19
=>x=-1
c: =>48x^2-12x-20x+5+3x-48x^2-7+112x=81
=>83x=83
=>x=1
tim x biet 4x2 -12x-7=0
4x2 - 12x -7 = 0
<=> 4x2 -14x +2x -7 = 0
<=> 2x(2x-7) + (2x-7) = 0
<=> (2x-7)(2x+1) = 0
<=> 2x-7 = 0 hoặc 2x+1 = 0
<=> 2x = 7 hoặc 2x = -1
<=> x= \(\frac{7}{2}\)hoặc x= \(\frac{-1}{2}\)
Vậy tập nghiệm của phương trình là S={\(\frac{7}{2}\);\(\frac{-1}{2}\)}