21=b/5 what is the variable b

Factorize 27x^3-16y^3

In 3 billion repetitions of an experiment, a random event occurred in 500 million cases. I know the probability of this event is 1/6 - what is the expected probability of the complement of the event?

If rain is falling at a rate of ¼ inch per hour, how much rain would you expect after 6 hours

The area of a rectangle is 63 yd2, and the length of the rectangle is 11 yd more than twice the width. Find the dimensions of the rectangle.

Use the substitution method to solve the system. {m+n=5m-n=3 What is the solution?

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.