Different ways to solve x+4=13

From 12:00 midnight to 6:00am the temperature decreased by 12 degree C if the original temperature was 12 degrees C which expression can be used to represent this situation

What is the value of s in the equation 3r = 10 + 5s, when r = 10?

Why does demand equal marginal revenue for perfectly competitive firms

The ratio between the number of children (c) on a field trip and number of teachers (t) on the trips is (14) / (3). There are 70 children on the field trip. How many teachers are on the grip?

I am a odd number i am less than 100 the sum of my digits is 12 i am a multiple of 15 what number am i?

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.