SOLUTION: Hi. I don't understand this problem and am unsure if I can write it correctly. I need to solve for the solution is x=__. sqrt 7x+36 = x+4. The problem is written as √7x+36=x

Algebra ->  Square-cubic-other-roots -> SOLUTION: Hi. I don't understand this problem and am unsure if I can write it correctly. I need to solve for the solution is x=__. sqrt 7x+36 = x+4. The problem is written as √7x+36=x      Log On


   

Question 462214: Hi. I don't understand this problem and am unsure if I can write it correctly. I need to solve for the solution is x=__.
sqrt 7x+36 = x+4. The problem is written as √7x+36=x+4. With the bar from the square root sign extending over the 7x+36.
Please help. Thanks so much
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The problem is written as √7x+36=x+4. With the bar from the square root sign extending over the 7x+36
----
sqrt(7x+36) = x+4
---
Square both sides to get:
7x+36 = x^2+8x+16
---
x^ + x -20 = 0
---
Factor:
(x+5)(x-4) = 0
---
x = -5 or x = 4
---
Check the "answers" in the original problem:
sqrt(7x+36) = x+4
x = -5 ?
sqrt(-35+36) = -5+4
sqrt(1) = -1
No
----
x = 4?
sqrt(28+36) = 4+4
sqrt(64) = 8
Yes
-------------------
Final Answer: x = 4
=============================
Cheers,
Stan H.
==============