SOLUTION: solve {{{sqrt(7x+36)}}}=x+4

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Question 368794: solve sqrt%287x%2B36%29=x+4
Answer by fractalier(6550) About Me  (Show Source):
You can put this solution on YOUR website!
From sqrt%287x%2B36%29=x%2B4
let us square both sides and get
7x+%2B+36+=+x%5E2+%2B+8x+%2B+16
Now collect terms and get
x%5E2+%2B+x+-+20+=+0 (Notice I flipped it)
Now factor and solve
%28x+%2B+5%29%28x+-+4%29+=+0
and
x = -5 or x = 4
For problems involving roots, YOU HAVE TO CHECK solutions.
Notice x = 4 works fine but x = -5 does not.