Question

Determinați x stiind ca:
a)5 supra x din 80 este100

Answer 1

5/x ori 80=100
5/X=100/80
simplifici 100/80=5/4
5/x=5/4 => x=4

Answer 2

$\frac{5}{x} 80=100 \\ \\ \frac{400}{x} =100=\ \textgreater \ 400=100x=\ \textgreater \ x=400:100=\ \textgreater \ x=4$