bài 1 :
b) (x-1/2 )2 = 0
<=> x - 1/2 = 0
<=> x = 0+ 1/2
<=> x = 1/2
c) ( x - 2 ) 2 = 1
<=> x -2 = 1
<=> x = 1 +2 = 3
d) ( 2x -1 )3 = -8
<=> ( 2x - 1) 3 = ( -2 ) 3
<=> 2x - 1 = -2
<=> 2x = -2+1 = -1
<=> x = -1/2
Bài 2 :
c) 32x-1=243
<=> 32x-1= 35
<=> 2x-1 = 5
<=> 2x = 6
<=> x = 6:2 = 3
Mk chỉ giải đc như vậy thôi
bạn thông cảm nhé !
Tìm các số hữu tỷ x,biết rằng:
a,\(\left(x-\dfrac{5}{3}\right):-1\dfrac{3}{4}=0\)
b,\(\left(x-\dfrac{1}{5}\right)\left(1\dfrac{3}{5}+2x\right)=0\)
c,\(\left(x-\dfrac{4}{7}\right):\left(x+\dfrac{1}{2}\right)>0\)
d,(2x-3):\(\left(x+1\dfrac{3}{4}\right)< 0\)
Tìm x, biết rằng:
a) \(\left(x-\dfrac{3}{4}\right)^2=0\)
b) \(\left(x-3\right)^2=1\)
c) \(\left(2x+1\right)^3=-8\)
d) \(\left(x-\dfrac{1}{4}\right)^2=\dfrac{1}{4}\)
tìm x \(\in\) Q biết
\(a,\left|2,5-x\right|=1,3\)
\(b,1,6-\left|x-0,2\right|=0\)
\(c,\left|x-1,5\right|+\left|2,5-x\right|=0\)
\(d,\left(x-\frac{1}{2}\right)^2=0\)
\(e,\left(x-2\right)^2=1\)
\(f\left(2x-1\right)^3=-8\)
1) Tìm x biết :
a) [ x ] + 1 = 5
b) ( [ x ] + 2 ) x ( 3 [ x ] - 1 ) = 0
2) Tìm x , y biết :
a) [ x ] + { y } = 1,5 và [ y ] + { x } = 3,2
b) x + y = 3,2 và [ x ] + { y } = 4,7
3) Tìm x để :
a) M = \(\left(2x-3\right).\left(\frac{3}{4}x+1\right)=0\)
b) N = \(\frac{\frac{2}{3}x-5}{3x+2}< 0\)
c) \(P=\left(\frac{3}{4}x+2\right).\left(\frac{2}{5}x-6\right)=0\)
d) \(Q=\frac{\left(x-3\right).\left(2x+5\right)}{7-x}>0\)
* Đây là bài phần nguyên, phần lẻ của một số.
Tìm x thuộc Z biết
a. \(\left(x-1\right)\times\left(2x-4\right)=0\)
b. \(\left(x^2+5\right)\times\left(x-5\right)=0\)
c. \(\left(x^2+5\right)\times\left(x^2-2\right)=0\)
d. \(\left(x^2-1\right)\times\left(x^2-9\right)< 0\)
e. \(\left|x^2-2x\right|=x\)
g. \(\left|2x+1\right|+\left|x+8\right|=4x\)
Tìm x:
a)\(-4.\left[2.\left(x-4\right)-3.\left(5x-1\right)\right]+2x-8=12\)
b)3x.2x=216
c)27<813:3x<243
d)(x-7)x+1-(x-7)x+11=0
Rút gọn:
\(A=\left[\left(\dfrac{3}{1+x}-\dfrac{x}{x^2+x+1}\right):\dfrac{2x^2+3x}{x+1}+\dfrac{3}{x+1}\right]\cdot\dfrac{x^2+x}{1+3x}\)
\(B=\left[\dfrac{a}{2a-6}-\dfrac{a^2}{a^2-9}+\dfrac{a}{2a-9}\cdot\left(\dfrac{3}{a}+\dfrac{1}{3-a}\right)\right]:\dfrac{a^2-5a-6}{18-2a^2}\)
ĐỀ 1:
1. Tính:
a. \(\dfrac{7}{23}\left[\left(\dfrac{-8}{6}\right)-\dfrac{45}{18}\right]\)
b. \(\dfrac{1}{5}:\dfrac{1}{10}-\dfrac{1}{3}\left(\dfrac{6}{5}-\dfrac{9}{4}\right)\)
c. \(\dfrac{3}{5}.\left(\dfrac{-8}{3}\right)-\dfrac{3}{5}:\left(-6\right)\)
d. \(\dfrac{1}{2}\left(\dfrac{4}{3}+\dfrac{2}{5}\right)-\dfrac{3}{4}\left(\dfrac{8}{9}+\dfrac{16}{3}\right)\)
e. \(\dfrac{6}{7}:\left(\dfrac{3}{26}-\dfrac{3}{13}\right)+\dfrac{6}{7}\left(\dfrac{1}{10}-\dfrac{8}{5}\right)\)
2. Tìm x, biết:
a. \(1\dfrac{2}{5}x+\dfrac{3}{7}=\dfrac{4}{5}\)
b. |x - 1,5| = 2
c. \(\dfrac{4}{5}-\left|x-\dfrac{1}{6}\right|=\dfrac{2}{3}\)
d. 3x . 2x = 216
e. \(\dfrac{1}{2}\left(x-\dfrac{1}{3}\right)+\dfrac{-1}{2}=\dfrac{3}{4}\)
* Lm nhanh nha
Ths you <3
a, \(\left(x+5\right)^3=-64\)
b,\(\left|2x-5\right|=8\)
c, \(\left|\dfrac{3}{4}x-\dfrac{1}{5}\right|=2\)
d, \(\left|3x-6\right|=x+4\)
e, \(\left|x-3\right|=2x+1\)
