b) \(x^3-6x^2+11x-12=0\)
\(\Leftrightarrow\)\(x^3-4x^2-2x^2+8x+3x-12=0\)
\(\Leftrightarrow\)\(x^2\left(x-4\right)-2x\left(x-4\right)+3\left(x-4\right)\)
\(\Leftrightarrow\)\(\left(x-4\right)\left(x^2-2x+3\right)=0\)
Ta có: \(x^2-2x+3\)
\(=\left(x-1\right)^2+2>0\)
\(\Rightarrow\)\(x-4=0\)
\(\Leftrightarrow\)\(x=4\)
Vậy...
bài 1 tìm x
a)6x^2-72x=0
b)-2x^4+16x=0
c)x(x-5)-(x-3)^2=0
d)(x-2)^3-(x-2)(x^2+2x+4)=0
tìm x biết
a, x(2x-7)-4x+14=0
b, x(x-1)+2x-2=0
c, 2x^3+3x^2+2x+3=0
d, x^3+6x^2+11x+6=0
Tìm x
a) 3x(4x - 3) - 2x(5 - 6x) = 0
b) 5(2x - 3) + 4x(x - 2) + 2x(3 - 2x) = 0
c) 3x(2 - x) + 2x(x - 1) = 5x(x + 3)
d) 3x (x + 1) - 5x(3 - x) + 6(x^2 + 2x + 3) = 0
1.x^3+4x^2+x-6=0
2.x^3-6x^2+11x-6=0
3.x^3-4x^2+x+6=0
4.x^3-3x^2+4=0
5.x-ab/a+b + x-bc/b+c + x-ca/c+a=a+b+c(voi a,b,c,>0)
6.x^2+2x+1/x^2+2x+2 + x^2+2x+2/x^2+2x+3=7/6
\(x^4+2x^3-5x^2+6x-3=0\)
\(2x^4-10x^3+11x^2+x-1=0\)
Bài 3 : Tìm x biết
a) (x-2)^2-x(x-3)=0
b) (x+3)(2x+1)-2(x-1)^2=0
c) (4x-5)^2=9(2-5x)^2
d) X^2-6x-13=0
e) (x+2)(x^2-2x+4)-x(x^2+2)=15
f) X^3-6x^2+12x-19=0
a)(6x^2+17x+12):(2x+3) b)(5x^2+13x-6):(5x-2) c)(-8x^2+22x-15):(2x-5) d)(14x^2-33x-5):(2x-5) e)(2x^3+7x^2+15x+6):(2x+1) f)(x^3+4x^2-11x-2):(x-2) g)(12x^3+2x^2+4x+3):(2x+1)
Giải phương trình
a) \(x^2-2x+1=0\)
b)\(1+3x+3x^2+x=0\)
c)\(x+x^4=0\)
d)\(x^3-3x^2+3x-1+x\left(x^2-x\right)=0\)
e)\(x^2+x-12=0\)
g)\(6x^2-11x-10=0\)
Tìm x:
a)2x3-18x=0
b)(3x-2).(2x+1)-6x.(x+2)=11
c)(x-1)3-(x+2).(x2-2x+4)=3.(1-x2)
