Ex 1.
.
[tex] \frac{6}{x} = \frac{y}{5} \\ \\ 128 - 3xy = k \\ \\ \\ [/tex]
=>
[tex] \frac{6}{x} = \frac{y}{5} \\ \\ x \times y = 6 \times 5 \\ \\ xy = 30[/tex]
Acum înlocuim XY aici:
[tex]128 - 3xy[/tex]
=
[tex]128 - 3(30) = \\ = 128 - 90 = \\ = 38[/tex]
Ex 2.
.
[tex] \frac{64}{90} \\ \\ \frac{64}{92} \\ \\ \frac{64}{94} \\ \\ \frac{64}{96} \\ \\ \frac{64}{98} [/tex]