(x3-6x2+12x-8)+9x2-1=(x3+3x2+3x+1)
x3-6x2+12x-8+9x2-1-x3-3x2-3x-1=0
(x3-x3)-(6x2-9x2+3x2)+(12x-3x)-(8+1+1)=0
9x-10=0
9x=10
x=\(\frac{10}{9}\)
Violympic toán 8
Các câu hỏi tương tự
1 tháng 12 2018 lúc 14:12
Tìm x biết:
1. (x-2)^2-(x-3)(x+3)=6
2. 4(x-3)^2-(2x-1)(2x+1)=10
3. (x-4)^2-(x-2)(x+2)=6
4.9(x+1)^2-(3x-2)(3x+2)=10
5. 3x +2(5-x)=0
6.x(2x-1)(x+5)-(2x^2+1)(x+4,5)=3,5
7, 3x^2-3x(x-2)=36
8. (3x^2-x+1)(x-1) +x^2(4-3x)=5/2
Tìm x, biết:
(4x-1)2-(3x+2)(3x-2)= (7x-1)(x+2)+(2x+1)2-(4x2+7)
(5x-1)(x+1)-2(x-3)2= (x+2)(3x-1)-(x+4)2+(x2-x)
(-x+5)(x-2)+(x-7)(x+7)= (3x+1)2-(3x-2)(3x+2)
(2x+3)2-(5x-4)(5x+4)= (x+5)2-(3x-1)(7x+2)-(x2-1)
(1-3x)2-(x-2)(9x+1)= (3x-4)(3x+4)-9(x+3)2
Tìm x
b) (x-5) (x-4) - (x+1)(x-2)=7
c) (3x-4)(x-2)=3x(x-9)-3
d)(x-3)(x^2+3x+9)+x(5-x^2)=6x
e) (3x-5)(x+1)-(3x-1)(x+1)=x-4
Giair pt:
c, x ( 3x-1) (3x+1) (3x+2) =8
d, (x+1) (2x+3) (2x+5) (x+3)=45
e,x4+ 3x3 - 15x2 - 19x + 3 = 0
f, \(\frac{1}{x^2+x}+\frac{1}{x^2+3x+2}+\frac{1}{x^2+5x+6}+\frac{1}{x^2+7x+12}=\frac{1}{3}\)
h,\(\frac{1}{x^2+9x+20}+\frac{1}{x^2+11x+30}+\frac{1}{x^2+13x+42}=\frac{1}{18}\)
Giải PT sau:a, 3x - 7 0b, 8 - 5x 0c, 3x - 2 5x + 8d, dfrac{3x-2}{3} dfrac{1-x}{2}e, ( 5x + 1)(x - 3) 0f, (x + 1)(2x - 3) 0g, 4x(x + 3) - 5(x + 3) 0h, 8(x - 6) - 2x(6 - x) 0i, dfrac{2}{x-1} + dfrac{1}{x} dfrac{2x+5}{x^2-x}k, dfrac{3}{x+2} - dfrac{2}{x-2} dfrac{2-x}{x^2-4}m, dfrac{3}{x} - dfrac{2}{x-3} dfrac{4-x}{x^2-3}n,dfrac{3}{2x+10}+ dfrac{2x}{x^2-25} dfrac{3}{x-5}u, dfrac{2}{x+3} - dfrac{3}{x-2} dfrac{x+4}{left(x+3right)left(x-2right)}
Đọc tiếp
Giải PT sau:
a, 3x - 7 = 0
b, 8 - 5x = 0
c, 3x - 2 = 5x + 8
d, \(\dfrac{3x-2}{3}\) = \(\dfrac{1-x}{2}\)
e, ( 5x + 1)(x - 3) = 0
f, (x + 1)(2x - 3) = 0
g, 4x(x + 3) - 5(x + 3) = 0
h, 8(x - 6) - 2x(6 - x) = 0
i, \(\dfrac{2}{x-1}\) + \(\dfrac{1}{x}\) = \(\dfrac{2x+5}{x^2-x}\)
k, \(\dfrac{3}{x+2}\) - \(\dfrac{2}{x-2}\) = \(\dfrac{2-x}{x^2-4}\)
m, \(\dfrac{3}{x}\) - \(\dfrac{2}{x-3}\) = \(\dfrac{4-x}{x^2-3}\)
n,\(\dfrac{3}{2x+10}\)+ \(\dfrac{2x}{x^2-25}\) = \(\dfrac{3}{x-5}\)
u, \(\dfrac{2}{x+3}\) - \(\dfrac{3}{x-2}\) = \(\dfrac{x+4}{\left(x+3\right)\left(x-2\right)}\)
Giải phương trình:
a) (x^2+3x+1).((4x-3)/(3x+1)+2)=(4x+7).((4x-3)/(3x+1)+2)
b)(x-1)/(x+2)-x/(x-2)=(5x-2)/(4-x^2)
1. ( x+1 ) (x2-x+1) -2x = x (x-1) (x+1 )
2. ( x-2)3+(3x-1)(3x+1) = (x+1)3
Giải phương trình:
(3x-1)2 -3(3x-2)=9(x+1)(x-3)
Bài 1: giải các phương trình sau
a,(3x-1)(x+3)=(2-x)(5-3x) d,(3x+5)(2x+1)=(6x-2)(x-3)
b,(x+5)(2x-1)=(2x-3)(x+1) e,(x+2)2+2(x-4)=(x-4)(x-2)
c,(x+1)(x+9)=(x+3)(x+5) f,(x+1)(2x-3)-3(x-2)=2(x-1)2