Substitution Problem:

x+5y=4

3x+15y=-1

Which algebraic expression represents "twice the sum of y and 9" A. 2+9y B. 2 (9y) C. 2 (y+9) D. 2 + (y+9)

Compute the volume of a sphere with a radius of 12 inches. 1728π in3 192π in3 576π in3 2304π in3

Lake Superior is the largest of the Great Lakes it covers a surface area of about 30,000 square miles. How can you show the estimated area of Lake Superior as a whole number multiplied by a power of ten? How can you use a pattern to find the answer?

The product of 32 and an unknown number subtracted from 435 is 179.

How many rectangles can you build with a prime number of square tiles?

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.