SOLUTION: Solve the equation. Check for extraneous solutions. square root of 5x+1 = x-4

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Question 155290: Solve the equation. Check for extraneous solutions.
square root of 5x+1 = x-4
Answer by oscargut(2103) About Me  (Show Source):
You can put this solution on YOUR website!
sqrt%285x%2B1%29=x-4
then
5x%2B1=%28x-4%29%5E2
then
5x%2B1=x%5E2-8x%2B16
then
-x%5E2%2B13x-15=0
then
x+=+%28-13+%2B-+sqrt%28+13%5E2-4%2A%28-1%29%2A%28-15%29+%29%29%2F%282%2A%28-1%29%29+
then
x+=+%28-13+%2B-+sqrt%28+13%5E2-4%2A%28-1%29%2A%28-15%29+%29%29%2F%282%2A%28-1%29%29+
then
x+=+%28-13+%2B-+sqrt%28109%29%29%2F%28-2%29+
x=11.72 (aprox) or x=1.28 (aprox)
Checking:
x-4 is positive if x=11.72 but is negative if x=1.28
sqrt%285x%2B1%29 is always positive so x=1.28 is a extraneous solution
and the only solution for the first equation is the first
Answer:x+=+%28-13+-+sqrt%28109%29%29%2F%28-2%29+