a) \(3^{x+1}=729\)\(\Leftrightarrow3.3^x=729\Rightarrow3^x=243\Rightarrow3^x=3^5\Rightarrow x=5\)
b) \(2^x+2^{x+1}+2^{x+3}=704\Rightarrow2^x+2^x.2+2^x.2^3=704\Rightarrow2^x\left(1+2+8\right)=704\)
\(\Rightarrow2^x.11=704\Rightarrow2^x=64\Rightarrow2^x=2^5\Rightarrow x=5\)
Tìm x ,biết A,2.x(x+1)-135=-200 B,4.x-5.(x-1)+15=13 C,2/3.x-1/4=3/5-7/8 D,1/2.(2.x-3)+105/2=-137/2
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
tìm x thuộc N biết:
a) 3 x : 3 = 81
b) x : 45 = 4
c) 3x . 32 = 729
d) 5x .625 = 3125
e) (2x + 1)3 = 729
g) x 1000= x2
h) (x-2)3= (x-2)2
Tìm x
a, ( 3 . x -1 ) . ( -1/2 .x + 5 ) = 0
b, 3. ( x - 1/2 ) - 5 ( x + 3 /5 ) = x + 1 /5
c, -5 . ( x + 1/5 ) - 1/2 . ( x - 2/3 ) = 3/2 . x - 5/6
d,3. ( 3 . x - 1/2 ) mũ 3 + 1/9 = 0
Tìm x biết
a,(2-x)-(2.x-5/2)-|-2|=x-1/4
b.2.(x-1/3)-1/3.x=-1/4-x
c,3/2:/-1|3.x+1/3|/=|5/3-2
d,(3/4-2.x)4-2=79
e,(-4)mũ x+3-1=15
bài 1 : tìm x biết
a, ( x - 2 ) : 2 x 3 = 6
b, X : ( hỗn số 3 1/2 x hỗn số 2 2/3 ) = 9/56
c, 1 + 3 + 5 + .....+ ( 2 x X + 1 ) = 625
bài 2 : tìm x biết
a, ( x - 1/2 ) x 5/3 = 7/4 - 1/2
b, 5 x X + X = 42
c, ( x+1 ) + ( x+ 3 ) + ( x + 5 ) + ....+ ( x + 11 ) = 58
bài 3 tìm x biết
a, X - 1,25 x 4 = 7,5
b, X = ( hỗn số 6 3/5 : 6 - 0 , 125 x 8 + hỗn số 2 2/15 x 0,03 ) x 2/11
c, ( X + 1 ) +(X + 2 ) + ( X + 3 ) + ....+(X + 20 ) = 750
Tìm x, biết: a) x = 1/4 + 5/13 b) x/3 = 2/3 + -1/7 c) x/3 = 16/24 + 24/ 36
d) x/15 = 1/5 + 2/3
Tính giá trị biểu thức:
a) A= 3 + 3^2 + 3^3 + 3^4 +...+3^100
b) B=5 x 4^15 x 9^9 - 4 x 3^20 x 8^9
____________________________
5 x 2^9 x 6^19 - 7 x 2^29 x 27^6
c) 2181 x 729 + 729 x 27^2
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3^2 x 9^2 x 243 + 3^6x 162 x 12 + 723 x 729
d) 1 + 1 + 1 + ..... + 1 + 1
__ __ __ __ ___
1 x2 2 x 3 3 x 4 98 x99 99 x 100
Tìm x biết:
\(a,\dfrac{4}{5}+x=\dfrac{2}{3}\)
\(b,\dfrac{-5}{6}-x=\dfrac{2}{3}\)
\(c,\dfrac{1}{2}x+\dfrac{3}{4}=\dfrac{-3}{10}\)
\(d,\dfrac{x}{3}-\dfrac{1}{2}=\dfrac{1}{5}\)
\(e,\dfrac{x+3}{15}=\dfrac{1}{3}\)
\(h,x+30\%x=-1,3\)
\(k,3\dfrac{1}{3}x+16\dfrac{1}{4}=13,25\)
\(m,\dfrac{x-6}{2}=\dfrac{50}{x-6}\)
\(n,x-13,4=24,5-6,7.5,2\)
\(p,15,7x+3,6x=-96,5\)
\(q,2,5x-11,6=-59,1\)
