Chú ý rằng:
- Nếu a 2 = b 2 thì a = b hoặc x = -b
Nếu a 3 = b 3 thì a = b
a ) x ∈ 3 2 ; 5 2 b ) x ∈ − 10 3 ; 8 3 c ) x ∈ − 2 5 ; 4 5 d ) x = 1 27
Chú ý rằng:
- Nếu a 2 = b 2 thì a = b hoặc x = -b
Nếu a 3 = b 3 thì a = b
a ) x ∈ 3 2 ; 5 2 b ) x ∈ − 10 3 ; 8 3 c ) x ∈ − 2 5 ; 4 5 d ) x = 1 27
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
Bài 1. Tìm x,y ϵ Z biết:
a) xy - 2x - y = 1
b) y ( x - 1 ) - x = 8
c) xy - 3x + 2y = 11
d) 2/50 + 2/48 + 2/154 + ... + 2/x(x+3) = 202/1540
e) ( 1/ 1 . 2 . 3 . 4 + 1/ 2 . 3 . 4 . 5 + 1/ 3 . 4 . 5 . 6 + ... + 1/ 7 . 8 . 9 . 10 ) . x = 119/720
Trình bày đầy đủ nhé =)))))
Tìm x biết:
\(a,\dfrac{4}{5}+x=\dfrac{2}{3}\)
\(b,\dfrac{-5}{6}-x=\dfrac{2}{3}\)
\(c,\dfrac{1}{2}x+\dfrac{3}{4}=\dfrac{-3}{10}\)
\(d,\dfrac{x}{3}-\dfrac{1}{2}=\dfrac{1}{5}\)
\(e,\dfrac{x+3}{15}=\dfrac{1}{3}\)
\(h,x+30\%x=-1,3\)
\(k,3\dfrac{1}{3}x+16\dfrac{1}{4}=13,25\)
\(m,\dfrac{x-6}{2}=\dfrac{50}{x-6}\)
\(n,x-13,4=24,5-6,7.5,2\)
\(p,15,7x+3,6x=-96,5\)
\(q,2,5x-11,6=-59,1\)
bài 1 :tìm x,y biết
a) (5x+1)=\(\dfrac{36}{49}\) b) (x-2/9) = (2/3) c)(8x-1) 2x+1= 5^2 x+1
d) (x-3,5)^x+(y - 1/10)^4=0
Tìm x biết
a) (x-1/2)^2=4
b) 10/1/2-(x+1/3)^2=1/1/2
c) (x-1/5)^2+17/25=26/25
d) 1/5/27+(3x-7/9)^3=24/27
tính :
a) 1/7 : 5/17 - 3/2 . ( 1/6 - 7/12 )
b) 25/77 - ( 1/5 - 7/15 ) : 10/11 : |-3/4|
c) 4/7 + 15/4 - 11/4 + 3/7 -1/2 + 1/3
tìm x biết :
a) 3/4 . x + 1/2 =3/5
b) x - 5/4 = 1/3 - 3/4 .x
c) -2/3 . ( x - 1/4 ) = 1/3 . ( 2x-1)
Tìm x biết.
a,(3x-10)*-1/2x+5=0
b,-5x*(x+1/5)-1/2*(x+5)=-x+1/5
c,2*|1/2x-1/3|-3/2=1/4
d,|20/9-x|=1/12+1/20+1/30+1/42+1/56+1/72
e,1/2*3*x+1/3*4*x+1/4*5*x+.....+1/49*50*x=1
MÌNH CẦN GẤP.
Tìm x biết :
a, (2/3) - (5/3).x = 1/2.( 7/5.x + 5/3 )
b, 1/2.(x+2) - 4.(x - 1/4 ) = (1/2).x
c, (x-3).(x - 1/2) = 3.(1/3.x)
1.Tìm x thuộc Z:
a)1+2+3+...+x=0
b)(x-1)+(x+1)+(x+2)+(x+3)+...+100=99
c)25.(x+5)=(7+3x)-(5x+4)
d)x.(x-1)-4(x+2)=3(2x-1)-x(4-x)
2.Tìm x thuộc Z:
a)(3-x).|3+x|=0
b)(x2+5).(x3+27)=0
c)(2x-4).(12-3x)>0
d)(x2-1).(x2+1).(x2+10).(x2+10).(x2+20)<0
3.Tìm a, b thuộc Z
a)a.(2b-1)=5
b)a2-a.b+b=7
c)a.(3b+1)+3(b-1)=10
d)2a+a.b-3b=11
Ai làm được câu nào thì cố giúp mình nhé mai phải nộp rồi!