( X - 2 )^2 = A ; A> 0
A^2 + 3A - 10 = 0
D = 9 + 40 = 49 ; √ D = 7
A1 = ( - 3 + 7 ) : 2 = 2 ( > 0 )
A2 = ( - 3 - 7 ) : 2 = - 5 ( < 0 )
( X - 2 )^2 = 2
X^2 - 4X + 4 - 2 = 0
X^2 - 4X + 2 = 0
D = 16 - 8 = 8
√ D = √ 8 = 2 √ 2
X1 = ( 4 + 2 √ 2 ) : 2 = 2 + √ 2
X2 = ( 4 - 2 √ 2 ) : 2 = 2 - √ 2