Tìm x biết:
5^x+1 5^2x + 2.5^3x = 875
Tìm x biết:
5^x+1 5^2x + 2.5^3x = 875
5^x+15^2x+2×5^3x=875
Tìm x, biết:
A) (x -1)^3+(2-x)(4+2x+x^2)+3x(x+2)=17
B) (x+2)(x^2-2x+4)-x(x^2-2)=15
C) (5x-2)(5x+2)-(5x+3)(5x-4)=8
D) (4x-3)(4x+2)+(4x+5)(1-4x)=2.5^2
Tìm x biết:
a) 5^x+1 - 2.5^x = 75.
b)9^x+1 - 5.3^2x = 324.
a) 5x + 1 - 2.5x = 75
<=> 5x.5 - 2.5x = 75
<=> 5x.3 = 75
<=> 5x = 25
<=> 5x = 52
<=> x = 2
Vậy x = 2
b) 9x + 1 - 5.32x = 324
<=> (32)x + 1 - 5.32x = 324
<=> 32x + 2 - 5.32x = 324
<=> 32x.32 - 5.32x = 324
<=> 32x . 4 = 324
<=> 32x = 81
<=> 32x = 34
<=> 2x = 4
<=> x = 2
Vậy x = 2
Tìm x Thuộc N biết:
a) 10+2x=4^5:4^3
b) 130-(100+x) =25
c) 2^2.(x+3^2)-5=55
d) 7^2-7(13-x) =14
e) 240:(x-5)=2^2.5^2-20
f) 250-10(24-3x):15=244
g) 6^2x-5^2x=11.2^2-70
h) 2^3x+5^2x=2(5^2+2^3)-33
Ai làm nhanh nhất em sẽ tick cho ạ
a) 10+2x=45:43
10+2x=42
10+2x=16
2x=16-10
2x=6
x=6:2
x=3
vậy x=3
b)130-(100+x)=25
100+x=130-25
100+x=105
x=105-100
x=5
vậy x=5
c)22.(x+32)-5=55
4.(x+9)=55+5
x+9=60:4
x+9=15
x=15-9
x=6
vậy x=9
d)72-7(13-x)=14
49-7(13-x)=14
7(13-x)=49-14
13-x=35:7
13-x=5
x=13-5
x=8
vậy x=8
Tìm số tự nhiên x , biết :
(2x- 6)5 = ( 2x - 6 )2
33x-4 - x0 = 8
52x-3 - 2. 52 - 2.52 = 52 . 3
(2x - 6)5 = (2x - 6)2
=> (2x - 6)5 - (2x - 6)2 = 0
=> (2x - 6)2.[(2x - 6)3 - 1] = 0
=> \(\orbr{\begin{cases}\left(2x-6\right)^2=0\\\left(2x-6\right)^3-1=0\end{cases}}\)
=> \(\orbr{\begin{cases}2x-6=0\\\left(2x-6\right)^3=1\end{cases}}\)
=> \(\orbr{\begin{cases}2x=6\\2x-6=1\end{cases}}\)
=> \(\orbr{\begin{cases}x=3\\2x=7\end{cases}}\)
=> \(\orbr{\begin{cases}x=3\\x=\frac{7}{2}\left(ktm\right)\end{cases}}\)
33x - 4 - x0 = 8
=> 33x - 4 - 1 = 8
=> 33x - 4 = 8 +1
=> 33x - 4 = 9
=> 33x - 4= 32
=> 3x - 4 = 2
=> 3x = 2 + 4
=> 3x = 6
=> x = 6 : 3 = 2
Tìm x biet:
a,5/2x+x=32/15
b,x-7/2x=-32/15
c,-7/3x-7/4x+11/3=18/5
d,-5/6-3x=2/3
e,2x-5/9=-2/3
f,1/2-2/3x=7/12
g,7-|2x-3|=4
h,(19x+2.5^2):14=(13-8)^2-4^2
i,3/4x-2/3=2/7.1/6+5/7.1/6
k,(x+1/2).(2/3-2x)=0
l,x/2013-1/10-1/15-1/21-........-1/120=5/8
2.Tìm x biết
a.|2x-5|=x+1
b.|3x-2|-1=2x
c.|x-5|+5=x
d.|3x-5|=3x-5
a) \(\left|2x-5\right|=x+1\)
<=> \(\orbr{\begin{cases}2x-5=x+1\left(x\ge\frac{5}{2}\right)\\5-2x=x+1\left(x< \frac{5}{2}\right)\end{cases}}\)
<=> \(\orbr{\begin{cases}x=-6\left(ktm\right)\\3x=4\end{cases}}\)
<=> \(x=\frac{4}{3}\left(tm\right)\)
b) \(\left|3x-2\right|-1=2x\) <=> \(\left|3x-2\right|=2x+1\)
<=> \(\orbr{\begin{cases}3x-2=2x+1\left(x\ge\frac{2}{3}\right)\\2-3x=2x+1\left(x< \frac{2}{3}\right)\end{cases}}\)
<=> \(\orbr{\begin{cases}x=-3\left(ktm\right)\\5x=1\end{cases}}\) <=> \(x=\frac{1}{5}\left(tm\right)\)
c) \(\left|x-5\right|+5=x\) <=> \(\left|x-5\right|=x-5\)
<=> \(\orbr{\begin{cases}x-5=x-5\left(x\ge5\right)\\5-x=x-5\left(x< 5\right)\end{cases}}\)
<=> \(\orbr{\begin{cases}0x=0\\2x=10\end{cases}}\) <=> 0x = 0 (luôn đúng) hoặc x = 5 (ktm)
Vậy x \(\ge\)5
d) \(\left|3x-5\right|=3x-5\) <=> \(\orbr{\begin{cases}3x-5=3x-5\left(x\ge\frac{5}{3}\right)\\5-3x=3x-5\left(x< \frac{5}{3}\right)\end{cases}}\)
<=> \(\orbr{\begin{cases}0x=0\left(luônđúng\right)\\6x=10\end{cases}}\)
<=> \(\orbr{\begin{cases}x\ge\frac{5}{3}\\x=\frac{5}{3}\left(ktm\right)\end{cases}}\)Vậy x \(\ge\)5/3
Tìm x,biết 5 mũ 2x-3 - 2.5 mũ 20=5 mũ 20.3