Question

If x is equal to 7plus 4 root 3 then find x minus 1 upon x

Answer 1

i ,

x = 7 + 4√3 ----( 1 )

1/x = 1 / ( 7 + 4√3 )

Rationalize the denominator,

1/x = ( 7 - 4√3 ) / ( 7 + 4√3 )( 7 - 4√3 )

= ( 7 - 4√3 ) / [ 7² - ( 4√3 )² ]

= ( 7 - 4√3 ) / [ 49 - 48 ]

1/x = 7 - 4√3 ----( 2 )

Therefore ,

x + 1/x = ( 1 ) + ( 2 )

= 7 + 4√3 + 7 - 4√3

= 14

hope this helps you

Answer 2

Answer:

∴ x-1/x = 14

Step-by-step explanation:

Given,

x = 7+4√3

x-1/x = ?

Now,

x-1/x = (7+4√3)+1/(7+4√3)

        = [(7+4√3)²+1]/(7+4√3)

        = (49+56√3+48+1)/(7+4√3)

        = (98+56√3)/(7+4√3)

        = 14(7+4√3)/(7+4√3)

        = 14