1. Daca a, b, c ∈ Q+, a/4=7/b si 10/c=ab/14, calculati c.
a/4=7/b
ab=4x7=28
10/c=ab/14
10/c=28/14=2
c= 10:2=5
2. Determinati numarul x din proportiile:
a). 2/5=4/x; x=4x5/2=10
b). 10/x=5/6; x=10x6/5=12
c). x/25=2/5; x=25x2/5=10
d). 3,5/2,5=x/10 x=3,5x10/2,5=14