SOLUTION: the question says solve: 2X+6 (under a square root)- X-6(under a square root)=3 My teacher got X=15 but I can not figure out how he came to that conclusion, could you help me plea

Question 80094: the question says solve: 2X+6 (under a square root)- X-6(under a square root)=3
My teacher got X=15 but I can not figure out how he came to that conclusion, could you help me please?
Answer by Earlsdon(6294) (Show Source): You can put this solution on YOUR website!
Solve for x:
First, isolate the radicals if possible. Here, you can add to both sides.
Now square both sides to remove the radicals, well...some of them.
Simplify this. Subtract x from both sides.
Subtract 3 from both sides.
Square both sides again to remove the remaining radical.
Simplify.
Subtract 36x from both sides.
Add 216 to both sides.
Now factor this quadratic equation.
Apply the zero products principle.
Add 15 to both sides.

Your teacher is correct!
RELATED QUESTIONS
f (10) (10)+6+3 - all under square root. the answer I got was 19 square root. but the... (answered by Alan3354,jim_thompson5910)

square root of x+7=square root of 2x-3 (+2) not under the square... (answered by lynnlo)

trying to figure out how to work the problem out my soultion to #54 was x=-3+/- square... (answered by elima)

i tried doing a square root tree but that didn't work. the question 3 square root 56,... (answered by Alan3354,MathLover1)

How do you solve (x-1/2)�=1 i've tried to square root both sides i put them under the... (answered by stanbon)

Solve: √x-6 + √x = 6 (x-6 is all under the square... (answered by Edwin McCravy,solver91311)

Hi, I need help with several questions. Solve for x. 6^(log_6 of x^2) = x+30 I'm not... (answered by lwsshak3)

square root of (2x+3) = x I got x = -1, 3 but my answer sheet says only x = 3... (answered by Leaf W.)

Solve: Square Root of (x+3) = 2x only (x+3) is under the Square Root Thank you (answered by MathTherapy)