\(x^2+2x+1=9\)
\(\Leftrightarrow x^2+2x+1-9=0\)
\(\Leftrightarrow x^2+2x-8=0\)
\(\Delta=b^2-4ac=2^2-4.\left(-8\right)=36>0\)
\(\Rightarrow Pt\) có 2 nghiệm phân biệt
\(\left\{{}\begin{matrix}x_1=\dfrac{-b+\sqrt{\Delta}}{2a}=\dfrac{-2+6}{2}=2\\x_2=\dfrac{-b-\sqrt{\Delta}}{2a}=\dfrac{-2-6}{2}=-4\end{matrix}\right.\)
Vậy \(S=\left\{2;-4\right\}\)
1: 3/x+1 + 2/x+2 = 5x+4/x2+ 3x + 2
2: 2/3x + 1 - 15/6x2-x-1 = 3/2x - 1
3: 9/3x - 1 - 5-x/3x2-4x+1 = 4/x+ 1
4:5/x - 2 + 2/x+4 = 3x/x2 + 2x - 8
5: 4/x+6 + 1/x - 3 = 9/x2 + 3x - 18
6:x/x-3 - 2x2 +9/2x2 - 3x - 9= 1/2x + 3
a)4/x+2+2/x-2+5x-6/4-x2 ; b)1-3x/2x+3x-2/2x-1+3x-2/2x-4x2 ; c)1/x2+6x+9+1/6x-x2-9+x/x2-9
Bài 2: Tìm x biết:
1,x\(^2\)+4x+4=25
2,(5-2x)\(^2\)-16=0
3,(x-3)\(^3\)-(x-3)(x\(^2\)+3x+9)+9(x+1)\(^2\)=15
4,3(x+2)\(^2\)+(2x-1)\(^2\)-7(x-3)9x+3)=36
5,(x-3)(x\(^2\)+3x+9)+x(x+2)(2-x)=1
6,(2x+1)\(^2\)-4(x+2)\(^2\)=9
7,(x+3)\(^{^{ }2}\)-(x-4)(x+8)=1
giải các phương trinh sau :
a) 3(2x - 1 ) - 2 (1 - x ) = x + 9
b) -3 ( 2x - 1 ) - 2 (1 - x ) = x + 9 ( 1 - x )
c) ( 1 - x ) ( 2x - 1 ) - 2 (2 - x ) ( 2 + x ) = x = 9
giải các phương trinh sau :
a) 3(2x - 1 ) - 2 (1 - x ) = x + 9
b) -3 ( 2x - 1 ) - 2 (1 - x ) = x + 9 ( 1 - x )
c) ( 1 - x ) ( 2x - 1 ) - 2 (2 - x ) ( 2 + x ) = x = 9
Giải phương trình
a) 2x-1/x+1 = -2x+1/x-5
b) 1/x-3 + 2/x^2-9 = x/x^2-2x-3
Bài 3.
1.A=(x-3).(x+3)+15-x^2
2. B=(x-1).(x^2+x+1)-x.(x^2+2)+2x
3. C=92x-1).(4x^2+2x+1 ) -x.(8x2 +1)+x
4.(2x-3).(4x^2+6x+9)-2x.(4x^2-1)=2x-27
5. (x-3).(x^2+3x+9)=x^3-27
ghi rõ cách làm nha
a, x^2-36/2x+10*3/6-x
b,5x-15/4x+4:x^2-9/x^2+2x+1
c,3-2x/ x^2-9 + 1/2x-6
d, -5/4+2y + y-2/2y+y^2
Tìm x biết:
a, 16x² – 9(x + 1)²= 0
b, x2 (x – 1) – 4x2 + 8x – 4 = 0
c, x(2x – 3) – 2(3 – 2x) = 0
d, (x – 3)(x² + 3x + 9) – x(x + 2)(x – 2) = 1
e, 4x² + 4x – 6 = 2
f, 2x² + 7x + 3 = 0
Tìm x bt: (2x+1)^2 + 2.(2x+1).(x+1) + (x-1)^2=9
