Răspuns: 2019
Explicație pas cu pas:
3 × 3 + 3 : 3 + 3 × (a : 3 - 3) = 2020
9 + 3 : 3 + 3 × (a : 3 - 3) = 2020
9 + 1 + 3 × (a : 3 - 3) = 2020
10 + 3 × (a : 3 - 3) = 2020
3 × (a : 3 - 3) = 2020 - 10
3 × (a : 3 - 3) = 2010
(a : 3 - 3) = 2010 : 3
a : 3 - 3 = 670
a : 3 = 670 + 3
a : 3 = 673
a = 673 × 3
a = 2019
