SOLUTION: square root of 5 more than twice a number is 7

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Question 994111: square root of 5 more than twice a number is 7
Found 2 solutions by Theo, MathTherapy:
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
7 = 2x + sqrt(5)

subtract 2x from both sides of the equation to get:

7 - 2x = sqrt(5)

square both sides of the equation to get:

(7-2x)^2 = 5

simplify the left side of the equation by squaring it to get:

49 - 28x + 4x^2 = 5

subtract 5 from both sides of the equation to get:

49 - 5 - 28x + 4x^2 = 0

combine like terms to get:

44 - 28x + 4x^2 = 0

rearrange the terms in descending order to get:

4x^2 - 28x + 44 = 0

factor out the gcf to get:

4 * (x^2 - 7x + 11) = 0

divide both sides of the equation by 4 to get:

x^2 - 7x + 11 = 0

factor the quadratic using the quadratic formula to get:

x = 4.618 and x = 2.382

answers are rounded to the third decimal place.

here's some info on the quadratic formula.

http://www.regentsprep.org/regents/math/algtrig/ate3/quadformula.htm




Answer by MathTherapy(10555) About Me  (Show Source):
You can put this solution on YOUR website!

square root of 5 more than twice a number is 7
Number: highlight_green%2822%29