13x + 9 - 5 equals 12 x - 4

I need the steps

A swimming pool is open for 7 1/2 hours a day. Each lifeguard will stay on duty for 1 1/2 hours. How many lifeguards will be needed for one day?

Which ratio is not equivalent to the other three? A. 2/5 B. 12/15 C. 6/15 D. 18/45

How are 12 fl oz equivalent to 335 ml

3x - 1 - 4x = - 2x + 7x - 4

1435.783 to the nearest cent

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.