👤

180°-(3x+30°+140°-5x)=90°

Răspuns :

180°-(3x+30°+140°-5x)=90°

180- ( 90+140-5x)=90
180-(230-5x)=90
180-90=230-5x
90= 230-5x
5x=230-90
5x=140
x=140:5
x= 28