radical( 2x + 3)² = | 2x + 3|
atunci | 2x +3| = 11
daca 2x+ 3 =11 2x +3 = -11
2x = 8 2x = - 14
x = 4 x = - 7
S = { -7 ; 4 }
med . aritm = ( 7 - √13 + 7 + √13) / 2 = 14 /2 = 7
( 7 - √13) ·( 7 +√13) = 7² - √13² = 49 - 13 = 36
notam a · b
med. geom = √ab = √36 = 6
