a/7=b/24=c/25=x, zicem ca sunt direct proportionale=>a=7x b=24x c=25x
a). (7x)²+(24x)²=(25x)² , ridici la putere numerele pe care le stim adica 7, 24 si 25
49x+576x=625x ceea ce e adevarat
b). a+b-c=0.6
7x+24x-25x=0.6
31x-25x=0.6
6x=0.6 x=0.6:6
x=0.1=> a=0.7
b=2.4
c=2.5
