SOLUTION: Let f(x) = (x � 2)2. Find x such that f(x) = 25

Question 224459: Let f(x) = (x � 2)2. Find x such that f(x) = 25
Answer by chibisan(131) (Show Source): You can put this solution on YOUR website!
Let f(x) = (x � 2)2. Find x such that f(x) = 25
since f(x)=25
(x-2)2 = 25
2x - 4 = 25
2x = 21
x = 21/2

or maybe u are refering to (x-2)^2?
(x-2)^2 = 25
x^2 - 4x + 4 = 25
x^2 - 4x - 21= 0
(x+3)(x-7)=0
x=-3 or x=7

test:
f(-3)=(x-2)^2
25= (-3-2)^2
25 =25

f(-7)= (x-2)^2
25 = (-7-2)^2
25 = 81 (x=7 is rejected)

x=-3 (ans)
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