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Flag Magical Mathematics[Interesting Approach]> solve for x 3 x +3 1-x -4 please solve it...
question mark

solve for x
3x+31-x-4
please solve it with explanation
thanks in advance for solution

Vishnudatta Thota , 7 Years ago
Grade 11
anser 3 Answers
Arun

Last Activity: 7 Years ago

Dear student
 
We can write it as
 
3^x + 3/3^x  - 4 = 0
 
Now assume 3^x = t
 
t + 3/t  - 4 = 0
 
t² -4t +3 = 0
 
(t-1) ( t-3) = 0
 
t = 1 and t = 3
 
Hence
 
3^x = 1
x = 0
 
&
 
3^x = 3
 
x = 1
 
 
Regards
Arun

Om

Last Activity: 7 Years ago

3x+31-x-4 =0
we can write the above equaion as 
3x+(31/3x)-4=0
Let 3x be y
y+(3/y)-4=0
y2+3-4y=0   ( by taking LCM)
(y-1)(y-3)=0  (by factorization)
y =  3  or 1
3x= 31  or  30   (as 30=1)
So x= 1or 0
 

Om

Last Activity: 7 Years ago

I forgot to mention the formulas 
These are the formulas that i used to solve your question
am/an=am-n         (this is the formula that i usen in 3rd line)
 
using this we can solve above equation in the question

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