Răspuns :
a) 3×{386+[48+2×(5×a-16×5)]}=1866-324 3×{386+[48+10a-160]}=1542 3×[386+(10a-112)]=1542 [386+(10a-112)]=1542÷3 (386+10a-112)=514 274+10a=514⇒10a=514-274⇒10a=240⇒a=240÷10⇒a=24 b)