SOLUTION: Please help with this: solve √(7x-8) = √(3x +12)

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Question 685853: Please help with this: solve

√(7x-8) = √(3x +12)

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Square both sides to get

7x - 8 = 3x + 12

Now solve for x

7x-8=3x%2B12 Start with the given equation.


7x=3x%2B12%2B8 Add 8 to both sides.


7x-3x=12%2B8 Subtract 3x from both sides.


4x=12%2B8 Combine like terms on the left side.


4x=20 Combine like terms on the right side.


x=%2820%29%2F%284%29 Divide both sides by 4 to isolate x.


x=5 Reduce.


So the *possible* solution is x=5

You need to check if it's actually the solution. You do so by plugging it back in like this

sqrt%287x-8%29+=+sqrt%283x%2B12%29

sqrt%287%285%29-8%29+=+sqrt%283%285%29%2B12%29

sqrt%2835-8%29+=+sqrt%2815%2B12%29

sqrt%2827%29+=+sqrt%2827%29 which is TRUE

So x=5 is indeed the solution.