In the following proportion, what does z equal?

3/7 = 15/z

I need the step by step answer for 1/3 (9x+3) = 3x+1

Let X and Y represent the tens digit and ones digit of a two-digit number, respectively. The sum of the digits of a two digit number is 9. If the digits are reversed, the new number is 27 more than the original number. What is the original number? A.

suppose a city with a population of 320,000 has been growing at a rate of 4% per year. If this rate continues, find the population of this city in 20 years.

Why does the headless horseman carry his head under his arm

23ft how many inches?

A newspaper reporter wants to know how popular the hobby of bird watching is in the city. He asked people at the local bird refuge if they watched birds as a hobby. Which of the following best explains whether the reporters data is valid or not?

I am very confused on how to figure out if y = 3/4x is proportional?

Alison wants to buy a mountain bike for $339.12. If she saves $28.26 each month, in how many months will she be able to buy the bike?

At 12 o'clock the temperature was 7°C. The temperature decreased by - 20°C. What is the new temperature?

Ashleys rentals charges $27.50 per hour to rent a surfboard and a wetsuit. Darlas surf shop charges $23.25 per hour to rent a surfboard plus $17 extra for a wetsuit.