\(2x\left(x+3\right)-x\left(x-3\right)=1\\ \Leftrightarrow2x^2+6x-x^2+3x-1=0\\ \Leftrightarrow x^2+9x-1=0\)
Ta có:
\(\Delta=9^2-4.1.\left(-1\right)=81+4=85>0\)
\(\Rightarrow\left\{{}\begin{matrix}x_1=\dfrac{-9+\sqrt{85}}{2}\\x_2=\dfrac{-9-\sqrt{85}}{2}\end{matrix}\right.\)
Tính (rút gọn )
1, 2x(3x-1)-(2x+1)(x-3)
2, 3(x^2-2x)-(4x+2)(x-1)
3, 3x(x-5)-(x-2)^2 -(2x+3)(2x-3)
4, (2x-3)^2+(2x-1) (x+4)
1.giải phương trình :
1)1 + 2/x-1 + 1/x+3=x^2+2x-7/x^2+2x-3
2)x/x^2+5x+6=2/x^2+3x+2 (x=3)
3)1/x^2+9x+20 - 1/x^2+8x+12=x^2-2x-33/x^2+8x+15 (x=-5,7)
4)x+5/3x-6 - 1/2=2x-3/2x-4 (x=25/7)
5)x-1/x^3+1 + 2x+3/x^2-x+1=2x+4/x+1 - 2(x=0)
Khai triển và thu gọn:
1, x(3x - 1) - 2x(x - 1) - (x - 2)2
2, x(2 + x) - (x - 1)(3 - x)-(3 - x)2
3, (2x - 1)2 - 2(2x - 1)(2x - 3) + (3 - 2x)2
P)(9-x)(x^2+2x-3) n)(-x+3)(x^2+x+1) O)(-6x+1/2)(x^2-4x+2) q)(6x+1)(x^2-2x-3) r)(2x+1)(-x^2-3x+1) U)(2x-3)(-x^2+x+6) s)(-4x+5)(x^2+3x-2) V)(-1/2x+3)(2x+6-4x^3)
a. 2x-3= 4x + 6
b. x + 2/4 - x + 3 - 1 - x/8 = 0
c.x(x - 1) + x(x + 3) + 0
d. x/ 2x -6- x/2x +2 = 2x/(x+1) (x-3)
a, x-3/4+2x-1/3=-x/6
b,(x-3)(2x-1)=(2x-1)(2x+3)
c,6/x-1-4/x-3+8/x^2-4x+3=0
Giải phương trình:
A) 1-x/x+1 +3 = 2x+3/x+1
B) (x+2)^2/2x-3 -1 = x^2-10/2x-3
C) 5x-2/2-2x + 2x-1/2 = 1 + x^2+x-3/x-1
D) 5-2x/3 - (x-1)(x+1)/1-3x = (x+2)(1-3x)/9x-3
E) x-3/x-2 + x-2/x-4 = -1
F) 1 + x/3-x = 5/(x+2)(3-x) + 2/x+2
G) x+1/x-1 - x-1/x+1 = 3x( 1 - x-1/x+1 )
H) 1-6x/x-2 + 9x-4/x+2 = x(3x-2)+1/x^2-4
I) 3x-1/x-1 - 2x+5/x+3 + 4/x^2+2x-3 = 1
a. 2x – 3 = 4x + 6 b. x 2 1 x x 3 4 8 = 0 c. x(x – 1) + x(x + 3) = 0 d. x x 2x 2x 6 2x 2 (x 1)(x 3)
a. 2x – 3 = 4x + 6 b. x+2/4-x+3-1-x/8=0 c. x(x – 1) + x(x + 3) = 0 d. x/2x-6-x/2x+2=2x/(x+1)(x-3)
1) 2x – (3 – 5x) = 4( x +3)
2) 5(2x-3) - 4(5x-7) =19 - 2(x+11)
3) 5x - 4(6-x)(x + 3) = (4-2x)(3-2x) + 2
4) (x - 1)3 - (3x + 2)(-12) = (x2 + 1)(x - 2) - x2
5) (3x -1)2 - (x +3)(2x-1) = 7(x + 1)(x -2) -3x
mn giúp mình vs
