Mathematics
14 Online
OpenStudy (anonymous):
Can someone please help me? 5+(sqrt(x+2))=8+(sqrt(x-7))
Join the QuestionCove community and study together with friends!
Sign Up
myininaya (myininaya):
solving for x I assume
myininaya (myininaya):
I would isolate one of the sqrt( ) things then square both sides
myininaya (myininaya):
\[\sqrt{x+2}=3+\sqrt{x-7}\]
square both sides
what do you get after doing just this step
OpenStudy (anonymous):
Do I square both sides?
myininaya (myininaya):
yes that is what I'm asking you to do :p
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
x+2=9+x-7?
myininaya (myininaya):
well that isn't exactly how you square the right hand side
OpenStudy (anonymous):
How would you do it then. That's the part I'm so confused on lol
myininaya (myininaya):
\[(\sqrt{x+2})^2=(3+\sqrt{x-7})^2 \\ x+2=(3+\sqrt{x-7})(3+\sqrt{x-7})\]
OpenStudy (anonymous):
Ok that would make sense..But then what..?
Join the QuestionCove community and study together with friends!
Sign Up
myininaya (myininaya):
multiply
OpenStudy (anonymous):
\[x+2=9+6(\sqrt{x-7})^2+x-7\]
OpenStudy (anonymous):
Is that right?
myininaya (myininaya):
well almost
myininaya (myininaya):
the square there shouldn't be on that radical part
Join the QuestionCove community and study together with friends!
Sign Up
myininaya (myininaya):
\[x+2=9+6 \sqrt{x-7}+x-7 \]
myininaya (myininaya):
now we want to isolate the square root item
and then square both sides again
myininaya (myininaya):
subtract x on both sides
+ 7 on both sides
- 9 on both sides
myininaya (myininaya):
\[7-9+2=6 \sqrt{x-7}\]
myininaya (myininaya):
combine like terms on left hand side
Join the QuestionCove community and study together with friends!
Sign Up
myininaya (myininaya):
divide both sides by 6
myininaya (myininaya):
and then square both sides
OpenStudy (anonymous):
You are my hero xD Thank you so much!!!
myininaya (myininaya):
make sure you check the answer by pluggin it into the original equation