Question 224746
Let f(x)=(x-2)^2.Find x such that f(x)=25


Step 1.  Given {{{f(x)=25=(x-2)^2=x^2-4x+4}}}


Step 2.  Subtract 25 from the above equation to yield a quadratic as follows


{{{x^2-4x+4-25=25-25}}}


{{{x^2-4x-21=0}}}


Step 3.  To solve, use the quadratic formula given as


{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}


where a=1, b=-4, and c=-21


*[invoke quadratic "x", 1, -4, -21 ]


Step 4.  ANSWER:  Solutions are 7 and -3.


I hope the above steps and explanation were helpful.


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And good luck in your studies!


Respectfully,
Dr J

http://www.FreedomUniversity.TV