We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive pseudonymised information about your use of our website. cookie policy and privacy policy.
 
+0  
 
0
411
1
avatar+578 

web2.0 calc did nothin for me

 

what is the solution of

\(\sqrt{5x+4} - \sqrt{x} = 4\)

 Dec 19, 2017
 #1
avatar+101431 
+3

√ [ 5x + 4 ] - √x  =  4          rearrange as

 

√[5x + 4 ]  =  4 + √x          square both sides

 

5x + 4  =  16  + 8√x  +  x

 

4x - 12  =  8√x           divide both sides by 4

 

x -  3  =  2√x             square both sides again

 

x^2  - 6x  +  9   =   4x

 

x^2  -  10x  +  9   =   0           factor

 

(x - 9) ( x - 1)   = 0

 

Setting both factors to 0  and solving for x leads to two possible solutions :

 

x  = 1     and  x   = 9

 

Checking these in the original equation.....only x  = 9   will be a true solution

 

 

cool cool cool

 Dec 19, 2017

9 Online Users

avatar
avatar
avatar