+0  
 
0
91
1
avatar+1015 

What is the solution of the equation?

AngelRay  May 26, 2018

Best Answer 

 #1
avatar+901 
+2

\(\sqrt{2x-5}+4=x\\ \sqrt{2x-5}+4-4=x-4\\ \sqrt{2x-5}=x-4\\ (\sqrt{2x-5})^2=(x-4)^2\\ 2x-5=x^2-8x+16\\ x^2-10x+21=0\\ (x-7)(x-3)=0\\ x_1=7, x_2 = 3 \)

We plug the solutions to verify:

 

\(\sqrt{2\cdot7-5}+4=7\\ \sqrt9+4=7\\ 3+4=7\\\) 

Seven works!

 

\(\sqrt{2\cdot3-5}+4=3\\ \sqrt1+4=3\\ 5\ne3\\\)  

 

Three doesn’t work. 

 

Therefore, the answer you seek is 7!

 

I hope this helped,

 

Gavin

GYanggg  May 26, 2018
 #1
avatar+901 
+2
Best Answer

\(\sqrt{2x-5}+4=x\\ \sqrt{2x-5}+4-4=x-4\\ \sqrt{2x-5}=x-4\\ (\sqrt{2x-5})^2=(x-4)^2\\ 2x-5=x^2-8x+16\\ x^2-10x+21=0\\ (x-7)(x-3)=0\\ x_1=7, x_2 = 3 \)

We plug the solutions to verify:

 

\(\sqrt{2\cdot7-5}+4=7\\ \sqrt9+4=7\\ 3+4=7\\\) 

Seven works!

 

\(\sqrt{2\cdot3-5}+4=3\\ \sqrt1+4=3\\ 5\ne3\\\)  

 

Three doesn’t work. 

 

Therefore, the answer you seek is 7!

 

I hope this helped,

 

Gavin

GYanggg  May 26, 2018

22 Online Users

avatar

New Privacy Policy

We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive information about your use of our website.
For more information: our cookie policy and privacy policy.