exercițiu 4
E de x = x+ 2

Răspuns:
E(x)=(x+2)²-(x-1)²-5x-3=
(x²+4x+4)-(x²-2x+1)-5x-3=
x²+4x+4-x²+2x-1-5x-3=x
E(`1)=1
E(2)=2
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E(2020)=2020
1+2+...+2020=sma Gauss=2020*2021/2=1010*2021=2041210
Explicație pas cu pas: