d) |x - 2| + |3 - x| = 1
\[D=\left ( \frac{1}{3\sqrt{x}-6} +\frac{1}{x-2\sqrt{x}}\right )\left ( \frac{1}{6} +\frac{1}{2\sqrt{x}}\right )\\ D=\left ( \frac{1}{3\left ( \sqrt{x}-2 \right )} +\frac{1}{\sqrt{x}\left ( \sqrt{x}-2 \right )}\right ).\frac{\sqrt{x}+3}{6\sqrt{x}}\\ D=\frac{\sqrt{x}+3}{3\sqrt{x}\left ( \sqrt{x}-2 \right )}.\frac{\sqrt{x}+3}{6\sqrt{x}}\\ D=\frac{\left ( \sqrt{x}+3 \right )^{2}}{18x\left ( \sqrt{x}-2 \right )}\\ D=\frac{x+6\sqrt{x}+9}{18x\sqrt{x}-36x}\]
A/ Đúng
B/ Sai
Rút gọn biểu thức
a) A= 39(x-y)^2-2(x+y)^2-(x-y)(x+y)
b) B= (x-1)^2-2(x-1)(x-3)+(x-3)^2
c) C= (2x+3)^2+(2x+3)(2x-6)+(x-3)^2
d) D= (x^2+x+1)(x^2-x+1)(x^4-x^2+1)(x^8-x^4+1)
tìm x: part 1 : a,(x^3)^2-(x+1)(x-1)=1 b,(x-2)^2-3(x-2)=0 c,(x+2)(x^2-2x+4)-x(x^2+2)=15 d,(x+1)^2-(x+1)(x-2)=0 e,4x(x-2017)-x+2017=0 f,(x+4)^2-16=0 part 2: a,x^3+27+(x+3)(x-9)=0 b,(2x-1)^2-4x^2+1=0 c,2(x-3)+x^2-3x=0 d,x^2-2x+1=6x-6 e,x^3-9x=0
Tính:
a) \((6{x^2} - 2x + 1):(3x - 1)\);
b) \((27{x^3} + {x^2} - x + 1):( - 2x + 1)\);
c) \((8{x^3} + 2{x^2} + x):(2{x^3} + x + 1)\);
d) \((3{x^4} + 8{x^3} - 2{x^2} + x + 1):(3x + 1)\)
1. Thu gọn:
a) 5x. (x-3) - x. (5x+1)
b) -3x. (x-1) - x. (x+1) + 4x. (x-2)
c) (3x-1). (x-2) + (x-1). (x+1)
d) (4x-3). (2x-5) - (8x-2). (x-1)
2. Tìm x:
a) 3x. (x-3) - x. (3x-2) = 2
b) -2x. (x+1) - 3. (1-x) + 2x2
c) (x-2). (x+2) + (3.x). (x+1) = 0
d) (2x-1). (x+3)- (x-2). (2x+1) = 10
1. Thu gọn:
a) 5x. (x-3) - x. (5x+1)
= 5x2 - 15x - 5x2 - x = -16x
b) -3x. (x-1) - x. (x+1) + 4x. (x-2)
= -3x2 + 3x - x2 - x + 4x2 - 8x
= -6x
Bài 1: Giải phương trình
a) (x+3) ( x-2 ) - 2(x+1)2 = ( x-3)2 - 2x2+ 4x
b) (x+1)3 - (x+2) (x-4) = (x-2) ( x2 + 2x +4 )+ 2x4
c) 4 ( x-1) (x+2) -5 (x+7) = (2x+3) 2 - 5x+3
d) (x+2)2 - 2( x+3) (x-4) = 5-x (x-3)
e) (1/ x^2-3x +3)+ (2/ x^2- 3x+4) = 6/ x^2 - 3x+5
Bài 2 Cho hình thang ABCD (AB// CD), AC giao BD tại O, O ∈ d ; d//AB ; d cắt AD tại I, cắt BC tại H. Cmr: OI = OH
c, (x+3)3 -(x-3)2 -(x-3)2 =6x+18 d, (x-1)3-x(x+1)2=5x(2-x)-11(x+2)
c: =>x^3+9x^2+27x+27-x^2+6x-9-x^2+6x-9=6x+18
=>x^3+7x^2+39x+9-6x-18=0
=>x^3+7x^2+33x-9=0
=>\(x\simeq0.26\)
d: =>x^3-3x^2+3x-1-x^3-2x^2-x=10x-5x^2-11x-22
=>x^3-5x^2+2x-1=-5x^2-x-22
=>x^3+3x+21=0
=>\(x\simeq2.40\)
Bài 1: Tìm x biết:
a) |x - 1| = 2x - 1
b) 2 |5-2x| -3 (x + 1) = 17
c) | | x - 2 |+ 3 | = 5
d) | 3 - 2x | = 3
Bài 2: Tìm x
a) | x - 1 | + | x + 2 | + | x - 3 | = 14
b) | x + 1 | + | x + 2 | + | x + 3 | + ... + | x + 10 | = 11x
c) | 39/2 - 3x^2 | = 15/2
d) | x + 4 | + | x + 10 | + | x + 101 | + | x + 999 | + | x + 1000 | = 2013
Bài 3: Tìm x
a) | x - 1 | < 5
b) | 1 - 2 x | < 3
c) | 2x + 3 | - 4 > 9
d) | 1/2 - x | + 3 > 7
\(\left|x-1\right|=2x-1\)
\(\Rightarrow\orbr{\begin{cases}x-1=2x-1\\x-1=-2x+1\end{cases}\left(đk:2x\ge\frac{1}{2}\right)}\)
\(\Rightarrow\orbr{\begin{cases}x=0\left(ktm\right)\\x=\frac{2}{3}\left(tm\right)\end{cases}}\)
vậy \(x=\frac{2}{3}\)
tìm x
b) (x + 3)2 - (x - 4)( x + 8) = 1;
c) 3(x + 2)2 + (2x - 1)2 - 7(x + 3)(x - 3) = 36;
d)(x - 3)(x2 + 3x + 9) + x(x + 2)(2 - x) = 1;
e) (x + 1)3 - (x - 1)3 - 6(x - 1)2 = -19.
hihi
b)(x+3)2-(x-4)(x+8)=1
\(\Rightarrow\)x2+6x+9-(x2+8x-4x-32)=1
⇒x2+6x+9-x2-8x+4x+32=1
⇒2x+41=1
\(\Rightarrow\)2x+41-1=0
\(\Rightarrow\)2x+40=0
⇒2x=-40
\(\Rightarrow\)x=\(\dfrac{-40}{2}\)
⇒x=-20