Răspuns:
Explicație pas cu pas:
Produsul mezilor = produsul extremilor =>
a) x/30 = 5/6 => x = (5·30):6 = 150:6 = > x = 25
b) 15/x = 5/6 => x = (15·6):5 = 90:5 = > x = 18
c) 9x/108 = 5/6 => x = (108·5):(9·6) = 540:54 => x = 10
d) (3x+2)/24 = 5/6 <=>
6·(3x+2) = 24·5 <=> 18x+12 = 120 <=>
18x = 120-12 <=> 18x = 108 => x = 108:18 => x = 6
