Tìm x biết: x+3.5+1000-23820+53=34234523423
tìm x thuộc N
a, 3x = 81
b,4x+1+4x =90
c,5x-1 + 3.5x-2 =1000
a)\(3x=81\) \(\Leftrightarrow3^x=3^4\)
\(\Rightarrow x=4\)
b)\(4x+1+4x=90\)( Có gì đó sai sai )
c)\(5^{x-1}+3.5^{x-2}=1000\)\(\Leftrightarrow5^{5-1}+3.5^{5-2}=1000\)
\(\Rightarrow x=5\)
Tìm x: a) 7/2:x=-2 1/3( hỗn số 2 một phần 3). b) 2/3-|2x+3|=-1/5. c)(3/2.4/3.5/4......2010/2009-x=1000
Tìm x, biết:
\(5^{x-11}-2.5^2=3.5^3\)
5x-11 - 2.52 = 3.53
5x-11 - 2.25 = 3.125
5x-11 - 50 = 375
5x-11 = 375 + 50
5x-11 = 425
.....
=>x thuộc rỗng nhé
5x-11-2.25=3.125
5x-11-50=375
5x-11=375+50
5x-11=425
đề sai rồi vì 5 mũ mấy cũng ko bằng 425 đâu
Tìm x, biết:
a ) 2 5 . x + 1 3 = 1 5 b ) 4 9 − 5 3 . x = − 2 c ) 1 5 + 5 3 : x = 1 2 d ) 5 7 : x − 3 = − 2 7
Tìm x, biết:
a ) 2 5 . x + 1 3 = 1 5 b ) 4 9 − 5 3 . x = − 2 ; c ) 1 5 + 5 3 : x = 1 2 d ) 5 7 : x − 3 = − 2 7
a ) x = 1 3 . b ) x = 22 15 . c ) x = 50 9 . d ) x = 5 19 .
tìm x biết x/1.3+x/3.5+x/5.7+.........+x/97.99=49/99
\(\frac{x}{1.3}+\frac{x}{3.5}+\frac{x}{5.7}+....+\frac{x}{97.99}=\frac{49}{99}\)
\(\Leftrightarrow\frac{x}{2}.\left(\frac{1}{1}-\frac{1}{3}+\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-\frac{1}{7}+....+\frac{1}{97}-\frac{1}{99}\right)=\frac{49}{99}\)
\(\Leftrightarrow\frac{x}{2}.\left(\frac{1}{1}-\frac{1}{99}\right)=\frac{49}{99}\)
\(\Leftrightarrow\frac{x}{2}.\frac{98}{99}=\frac{49}{99}\)
\(\Leftrightarrow\frac{x}{2}=\frac{49}{99}\div\frac{98}{99}\)
\(\Leftrightarrow\frac{x}{2}=\frac{1}{2}\)
\(\Leftrightarrow x=\frac{1}{2}\times2=1\)
\(\frac{x}{1\cdot3}+\frac{x}{3\cdot5}+...+\frac{x}{97\cdot99}=\frac{49}{99}\)
\(\Rightarrow\frac{x}{2}\left[\frac{1}{1\cdot3}+\frac{1}{3\cdot5}+...+\frac{1}{97\cdot99}\right]=\frac{49}{99}\)
\(\Rightarrow\frac{x}{2}\left[\frac{1}{1}-\frac{1}{3}+\frac{1}{3}-\frac{1}{5}+...+\frac{1}{97}-\frac{1}{99}\right]=\frac{97}{99}\)
\(\Rightarrow\frac{x}{2}\left[1-\frac{1}{99}\right]=\frac{49}{99}\)
\(\Rightarrow\frac{x}{2}\cdot\frac{98}{99}=\frac{49}{99}\)
\(\Rightarrow\frac{x}{2}=\frac{1}{2}\)
=> x = 1/2 * 2 = 1
tìm x biết ;
x nhân 6.5 + 3.5 = 20
x * 6,5 = 20 - 3,5
x * 6,5 = 16 ,5
x = 16 ,5 : 6,5
x = 2 ,538461...
k nha
X x 6,5 + 3,5 = 20
X x 6,5 = 16,5
X = 16,5 : 6,5
X = 2,5384....
tìm x và y biết |x-3.5| - |y-1.3| =0
|x-3.5| - |y-1.3| = 0
=> |x - 3,5| = |y - 1,3|
TH1 : x - 3,5 = y - 1,3
<=> x - y = 2,2
Th2 : x - 3,5 = -(y - 1,3)
<=> x - 3,5 = -y + 1,3
<=> x + y = 2,2
Tìm x , biết :
/x+1.5/+/x+2.5/+/x+3.5/+/x+4.5/=5x