notam cu a,b c laturile unui triunghi
invers proportionale =>a*1,2=b*0,9=c*1,5=k
a*1,2=k⇒a=k/1,2
b*0,9=k⇒b=k/0,9
c*1,5=k⇒c=k/1,5
a+b+c=94
k/1,2+k/0,9+k/1,5=94
10k/12+10k/9+10k/15=94
aducem la acelasi numitor si anume 180
150k+200k+120k=16920
470k=16920
k=16920:470
k=36
a=36/1.2=30
b=36/0.9=40
c=36/1.5=24
