Răspuns:
^(20x24-17x25)+X ^ :2+90:5:2=42
Explicație pas cu pas:
^ = paranteza patrata
^(20x24-17x25)+X^ :2+90:5:2=42
^(480-375)+X^:2+90:5:2=42
(105+X):2+90:5:2=42
(105+X):2+90:5=42x2=84
(105+X):2+90=84x5=420
(105+X):2=420-90=330
105+X=330:2=165
X=165-105
X=60
Coroana?
