9/25=(x-2/5)^2

Solution for 9/25=(x-2/5)^2 equation:

x in (-oo:+oo)

9/25 = (x-(2/5))^2 // - (x-(2/5))^2

9/25-(x-(2/5))^2 = 0

9/25-(x-2/5)^2 = 0

9/25-1*(x-2/5)^2 = 0

(-1*25*(x-2/5)^2)/25+9/25 = 0

9-1*25*(x-2/5)^2 = 0

20*x-25*x^2+5 = 0

20*x-25*x^2+5 = 0

5*(4*x-5*x^2+1) = 0

4*x-5*x^2+1 = 0

DELTA = 4^2-(-5*1*4)

DELTA = 36

DELTA > 0

x = (36^(1/2)-4)/(-5*2) or x = (-36^(1/2)-4)/(-5*2)

x = -1/5 or x = 1

5*(x+1/5)*(x-1) = 0

(5*(x+1/5)*(x-1))/25 = 0

(5*(x+1/5)*(x-1))/25 = 0 // * 25

5*(x+1/5)*(x-1) = 0

( 5 )

5 = 0

x belongs to the empty set

( x+1/5 )

x+1/5 = 0 // - 1/5

x = -1/5

( x-1 )

x-1 = 0 // + 1

x = 1

x in { -1/5, 1 }