What is 0.0000003105 in scientific notation?

Simplify each expression -6 (a+8)

the balance of an investment account is $308 more than 4 years ago. the current balance of the account is $4708. what was the balance 4 years ago?

A certain recipe calls for 2 1/3 cups of sugar, how much sugar is needed to make 1/3 of the recipe?

A car moving 50 miles per he speeds up steadily to 70 miles per he over a period of 30 minutes. how far did it travel during the 30 minute period of acceleration?

Rational numbers that are not integers are?

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.