Răspuns:
Explicație pas cu pas:
a = 1 + 3 + 5 + 7 + ..... + 2019
( 2019 - 1 ) : 2 + 1 = 2018 : 2 + 1 = 1010 termeni are suma
a = 1010 × ( 1 + 2019 ) : 2
a = 1010 × 2020 : 2
a = 1010 × 1010
a = 1010²
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b = 2 + 4 + 6 + 8 + ..... + 2020
b = 2 × ( 1 + 2 + 3 + ..... + 1010)
b = 2 × 1010 × ( 1 + 1010 ) : 2
b = 1010 × 1011
a < b, deoarece 1010² < 1010 × 1011 ( 1010 < 1011 )
