How to manipulate "12 = x - (square root of x)" into "x="
February 23, 2011 8:56 PM Subscribe
The solution to 12 = x - (square root of x) is 16, but how do I manipulate the equation to show that?
posted by Wanderboy to education (47 answers total) 3 users marked this as a favorite
I've been tiring myself out trying to manipulate this equation down to an "x =" form for too long, so I thought I'd try opening this up to the hive mind.
My first thought was that you could simply square both sides, but that leaves you with 144 = (x-sqrtx)(x-sqrtx) x^2 - 2*x^1.5 + x (not so helpful.) This is a frustrating problem for me because it's so obvious that it equals 16, but I can't make the math say so.
(I apologize in advance if the idiocy of this question offends all of the math majors and Ph.D. candidates that hang around here. I haven't taken a math class in a long time.)