math
posted by eve on .
I would really appreciate it, if someone helped me how to do this.
│x4│  │7x│ = 1

 x  4  7  x  = 1
 x  4  = 1 +  7  x 
Eliminate the absolute values:
First equation :
(  ( x  4 ) ) = ( 7  x ) + 1
Second equation :
( x  4 ) = ( 7  x ) + 1
Third equation :
( x  4 ) = (  ( 7  x ) ) + 1
Fourth equation :
( x  4 ) = ( 7  x ) + 1
You have equation ( x  4 ) = ( 7  x ) + 1 twice.
So you must solve 3 equations :
(  ( x  4 ) ) = ( 7  x ) + 1
( x  4 ) = ( 7  x ) + 1
( x  4 ) = (  ( 7  x ) ) + 1
(  ( x  4 ) ) = ( 7  x ) + 1
 x + 4 = 7  x + 1
 x + 4 = 8  x
 x + x = 8  4
0 = 4
NO SOLUTION
( x  4 ) = ( 7  x ) + 1
x  4 = 7  x + 1
x  4 = 8  x
x + x = 8 + 4
2 x = 12 Divide both sides by 2
x = 12 / 2 = 6
( x  4 ) = (  ( 7  x ) ) + 1
x  4 =  7 + x + 1
x  4 =  6 + x
x  x =  6 + 4
0 =  2
NO SOLUTION
Final solution :
x = 6 
Thank you A LOT!