SOLUTION: five times the square root of 1 less than a number is equal to 3 more than te number . find the number.

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Question 937803: five times the square root of 1 less than a number is equal to 3 more than te number . find the number.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
five times the square root of 1 less than a number is equal to 3 more than the number .
find the number.
:
Write an equation for exctly for what it says
5%2Asqrt%28x-1%29+=+x+%2B+3
square both sides
25(x-1) = (x + 3)^2
FOIL (x+3)(x+3)
25x - 25 = x^2 + 6x + 9
Combine like terms on the right
0 = x^2 + 6x - 25x + 9 + 25
0 = x^2 - 19x + 34
Factors to
(x-17)(x-2) = 0
Two solutions
x = 17
and
x = 2
:
We must check both solutions in the original equation
5%2Asqrt%2817-1%29+=+17+%2B+3
5%2Asqrt%2816%29+=+20
5*4 = 20; a good solution
and
5%2Asqrt%282-1%29+=+2+%2B+3
5%2Asqrt%281%29+=+5
5 * 1 = 5; also a good solution