Activity; 9. Solve each. 1. The weight of the rectangular block of metal varies jointly as the length, the width, and the thickness. If the weight of a 12 cm by 8 cm by 6 cm block of metal is 18 kg , find the weight of 16 cm by 10 cm by 4 cm .

Ms. Hendricks encourages her sixth-grade class to keep reading during breaks from school. She said that during a break lasting \( d \) days, they should each read \( 30 d \) minutes in total. This year, spring break is 9 days long. How many minutes should each student read during spring break? Write your answer as a whole number or decimal.

4. Alexandria, a car dealer, earns \( 40 \% \) commission of her luxury vehicles sales. Last year, her sales were \( \$ 480,000 \). What was the total dollar amount of her commission last year?

Ejemplo: Calcular la derivada de \[ f(x)=\sqrt{x} \]

Enter your answer in the blank. \( (a+b i)( \)

If \( \log _{10} y+3 \log _{10} x=2 \), express \( y \) in terms of \( x \) \( [2007 / 7] \)