SOLUTION: Find all real solutions: sqrt(x-3)+sqrt(x+5)=4

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Question 1053719: Find all real solutions:
sqrt(x-3)+sqrt(x+5)=4
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
sqrt(x-3)+sqrt(x+5)=4
square both sides
x-3+sqrt(x^2+2x-15)+x+5=16
2x+2(sqrt(x^2+2x-15)=16
2sqrt(x^2+2x-15)=-2x+14
divide by 2
x^2+2x-15=-x+7
square both sides
x^2+2x-15=x^2-14x+49
2x-15=-14x+49
-64=-16x
x=4
check
sqrt(1)+sqrt(9)=4, works