Question

Determinati numarul natural x din egalitatea: 2 x {99:[4+(5-x) x 2-1]}=18

Answer 1

2 x {99:[4+(5-x) x 2-1]}=18
99:[4+(5-x) x 2-1]=18:2
99:[4+(5-x) x 2-1] = 9
4+(5-x) x 2-1 = 99:9
4+(5-x) x 2-1 = 11
4+(5-x) x 2 = 11+1
4+(5-x) x 2 = 12
(5-X)×2 = 12-4
(5-X )×2 = 8
5-X = 8:2
5-X = 4
X = 5-4
X = 1