\(\sqrt\frac{5}{x+3}=\frac{4}{x+\sqrt4}\)
Please show how you got to your answer.
sqrt [(5) / (x + 3)] = 4 / [x + sqrt(4)]
sqrt [ (5) / (x + 3)] = 4/ [x + 2] square both sides
5 / [x + 3] = 16/ [x^2 + 4x + 4] cross-multiply
5 [ x^2 + 4x + 4 ] = 16[x + 3] simplify
5x^2 + 20x + 20 = 16x + 48
5x^2 + 4x -28 = 0 factor
[5x + 14] [ x - 2] = 0
Setting each factor to O we have that x = -14/5 or x = 2
However.....x = -14/5 produces a negative quantity on the right hand side of the original equation, and we can never get a negative out of the left hand side......so.......the two sides would have unequal signs, so x = -14/5 is not a soluition
So.......x = 2 is the only solution.....
Solve for x:
sqrt(5) sqrt(1/(x+3)) = 4/(x+2)
Cross multiply:
sqrt(5) sqrt(1/(x+3)) (x+2) = 4
Divide both sides by sqrt(5):
sqrt(1/(x+3)) (x+2) = 4/sqrt(5)
Divide both sides by x+2:
sqrt(1/(x+3)) = 4/(sqrt(5) (x+2))
Raise both sides to the power of two:
1/(x+3) = 16/(5 (x+2)^2)
Take the reciprocal of both sides:
x+3 = 5/16 (x+2)^2
Expand out terms of the right hand side:
x+3 = (5 x^2)/16+(5 x)/4+5/4
Subtract (5 x^2)/16+(5 x)/4+5/4 from both sides:
-(5 x^2)/16-x/4+7/4 = 0
The left hand side factors into a product with four terms:
-1/16 ((x-2) (5 x+14)) = 0
Multiply both sides by -16:
(x-2) (5 x+14) = 0
Split into two equations:
x-2 = 0 or 5 x+14 = 0
Add 2 to both sides:
x = 2 or 5 x+14 = 0
Subtract 14 from both sides:
x = 2 or 5 x = -14
Divide both sides by 5:
x = 2 or x = -14/5
sqrt(5) sqrt(1/(x+3)) => sqrt(5) sqrt(1/(3-14/5)) = 5
4/(x+2) => 4/(2-14/5) = -5:
So this solution is incorrect
sqrt(5) sqrt(1/(x+3)) => sqrt(5) sqrt(1/(3+2)) = 1
4/(x+2) => 4/(2+2) = 1:
So this solution is correct
The solution is:
Answer: | x = 2
sqrt [(5) / (x + 3)] = 4 / [x + sqrt(4)]
sqrt [ (5) / (x + 3)] = 4/ [x + 2] square both sides
5 / [x + 3] = 16/ [x^2 + 4x + 4] cross-multiply
5 [ x^2 + 4x + 4 ] = 16[x + 3] simplify
5x^2 + 20x + 20 = 16x + 48
5x^2 + 4x -28 = 0 factor
[5x + 14] [ x - 2] = 0
Setting each factor to O we have that x = -14/5 or x = 2
However.....x = -14/5 produces a negative quantity on the right hand side of the original equation, and we can never get a negative out of the left hand side......so.......the two sides would have unequal signs, so x = -14/5 is not a soluition
So.......x = 2 is the only solution.....