10. James bought a cheeseburger, fries and a drink for dinner. The cheeseburger was three times the price of the fries, and the drink and the fries were the same price. If the entire meal cost \( \$ 12.50 \), what was the price of each item?

Какое из приведенных неравенств будет линейным неравенством с одной переменной: \[ \begin{array}{l}\square \text { A) } 5+1<21 \\ \square \text { B) } x \leq 8 \\ \square \text { C) } x+5 \leq y \\ \square \text { D) } x y \leq \frac{4}{5} \\ \square \text { E) } y>13,1 \\ \square \text { F) } 5 x>5\end{array} \]

2. Demuestra que los siguientes puntos son vertices de un triángulo rectángulo. \( A(3,2), B(5,-4) \) y \( C(1,-2) \) \( A(2,4), B(4,8) \) y \( C(6,2) \) \( A(3,4), B(-2,-1) \) y \( C(4,1) \)

Scienze Un recipiente cilindrico contiene un miscuglio formato da limatura di ferro e polvere di zolfo. La polvere di zolfo ha una massa di 150 g , mentre la massa della limatura di ferro è \( \frac{1}{3} \) della massa totale. Calcola la massa dellali. matura di ferro e quella del miscuglio.

midpoint given the endpoints: \( (-1,5) \) and \( (-7,-7) \)

\begin{tabular}{l} Rewrite the expression with a positive rational exponent. Simplify, if possible. \\ \( 81^{-1 / 2} \) \\ \hline\( -\square \)\end{tabular}