aflati numarul necunoscut x:7-[5200:13-5*(360-2x]:20=2

Răspuns :

7-[5200:13-5*(360-2x]:20=2
5200:13-5*(360-2x]:20= 7-2
400-5×(360-2X) = 5×20
400-5×(360-2X) = 100
5×(360-2X) = 400-100
5×(360-2X) = 300
360-2X = 300:5
360-2X = 60
2X = 360-60
2X = 300
X = 300:2
X = 150