Lời giải:
$5^{x+1}-5^x=2.2^x+8.2^x$
$5^x(5-1)=2^{x+1}+2^3.2^x=2^{x+1}+2^{x+3}=2^{x+1}(1+2^2)$
$5^x.4=2^{x+1}.5$
$5^x.2^2=5^1.2^{x+1}$
$\Rightarrow x=1; 2=x+1$
$\Rightarrow x=1$
a,5^x+4-3×5^x+3=2×5^11
b,3×5^x+2+4×5^x-3=19×5^10
c,6×8^x-1+8^x-1=6×8^19+8^21
d,5×2^x+3×2^x+2=5×2^5+3×2^7
tìm x biết
1) x=-1/2 + 3/4 2) x - 1/5 = 2/11 3) x - 5/6 = 16/42 + -8/56
4) x/5 = 5/6 + -19/30 5) |x| - 1/4 = 6/18 6)x = -1/2 +3/4
7) x/15 = 3/5 + -2/3 8)11/8 + 13/6 = 85/x 9) x - 7/8 = 13/12
10) x - -6/15 = 4/27 11) -\(\dfrac{-6}{12}\)+ x = 9/48 12) x - 4/6 = 5/25 + -7/15
\(b) 5^{x+4} - 3 . 5^{x+3} = 2. 5^{11} \)
\(c) 2 . 3^{x+2} + 4 . 3^{x+1} = 10 . 3 ^{6}\)
\(d) 6 . 8 ^ {x-1} + 8 ^ {x+1} = 6 . 8^ {19} + 8 ^ {21}\)
Tìm x,biết:
a,3 / (x+2).(x+5) + 5 / (x+5).(x+10) + 7 / (x+10) . (x+17)= x / (x+2).(x+17)
x∉{-2 ; -5 ;-10 ; -17}
b,2 / (x-1). (x-3)+5 / (x-3).(x-8)+12 / (x-8).(x-20)-1 / x-20=-3/4
x∉{1;3;8;20}
c,x-1/2009 + x-2/2008 = x-3/2007 + x-4 / 2006
Tìm x, biết:
a) 3/(x+2)(x+5) + 5/(x+5)(x+10) + 7/ (x+10)(x+7) = x/(x+2)(x+17) với x thuộc {-2,-5,-10,-17}
b) 2/(x-1)(x-3 + 5/(x-3)(x-8) + 12/(x-8)(x-20) -1/x-20 =-3/4 với x thuộc {1,3,8,,20}
1, |x+1|+|x-2|+|x+3|=6
2, 2.|x+2|+|4-x|=11
3, |x-2|+|x-5|=3
4, |x-3|+|x+5|=8
5, |2x-1|+|2x-5|=4
B1:tìm x biết a, (-2+x^2)(x^2-2)(x^2-2)(x^2-2)(x^2-2)=1 b, (2x+3)(x-4)+(x-5)(x-2)=(3x-5)(x-4) c,(8x-3)(3x+2)-(4x+7)(x+4)=(4x+1)(5x-1) d, 2x^2+3(x-1)(x+1)=5x(x+1) e, (8-5x)(x+2)+4(x-2)(x+1)=(2+x)(2-x) f, 4(x-1)(x+5)-(x+2)(x+5)=3(x-1)(x+2)
Bài 1:
a, (-2+x\(^2\))(x\(^2\)-2)(x\(^2\)-2)(x\(^2\)-2)(x\(^2\)-2)=1
b, (2x+3)(x-4)+(x-5)(x-2)=(3x-5)(x-4)
c, (8x-3)(3x+2)-(4x+7)(x+4)=(4x+1)(5x-1)
d,2x\(^2\)+3(x-1)(x+1)=5x(x+1)
e,(8-5x)(x+2)+4(x-2)(x+1)=(2+x)(2-x)
f, 4(x-1)(x+5)-(x+2)(x+5)=3(x-1)(x+2)
tính
1/5 x 2^x + 1/3 x 2^x+1 = 1/5 x 2^7 + 1/3 x 2^8
Tìm giá trị nhỏ nhất của biểu thức:
4/ Q = |x + 1/5| - x + 4/7
5/ D = |x| + |8 - x|
6/ L = |x - 2012| + |2011 - x|
7/ E = |x - 2006/2007| + |x - 1|
8/ F = |x - 1/4| + |x - 3/4|
9/ M = |x - 1| + |x - 2| + |x - 3|
10/ G = |x + 3| + |x - 2| + |x - 5|
11/ P = |x + 1/2| + |x + 1/3| + |x + 1/4|
12/ N = |x - 1| + |x - 2| + |x - 3| + |x - 4|
13/ H = |x - 2| + |x - 3| + |x - 4| + |x - 5|
14/ I = |x + 5| + |x + 2| + |x - 7| + |x - 8|
15/ K = |x - 1| + |x - 2| + |x - 3| + ... + |x - 1996|
