14) 24/x =(m+n)m ⇔24/x =1+n/m ⇔24/x =1+a/b ⇔24/x=1+24/16⇒ x=48/5.
MN =2*48/5 =96/5 =192/10 = 19,2 . ( или иначе 96/5 =19 1/5 ).
15) 75/4
25/x =(m+n)m ⇔25/x =1+n/m ⇔25/x =1+a/b ⇔25/x=1+5/3 ⇒ x=75/8.
MN =2*75/8 =75/4 = 18.75. ( или иначе 96/5 =19 1/5 ).