1. 2· x = 52 ; x = 52:2 = 26
b. x / 4 = 2 x = 4 · 2 = 8
c. 10 ·( x -3 ) = 30 ; 10·x - 30 =30 ; 10·x = 60 ; x =6
2.E(x) = x³ -2x² + x = x · ( x² - 2x + 1 ) = x · ( x -1) ²
E( √2 + 1 ) = ( √2 +1 ) · ( √2 + 1 - 1 ) ² = ( √2 + 1 ) ·√4 = 2 · ( √2 + 1 )
c. E(x) = 0 daca x · ( x -1 ) ² = 0 ⇒ x₁ =0
x₂ = 1