In an old story, a man puts 2 grains of rice on the first space of a chess board. he puts 4 grains on the second space, 8 grains on the third space, and so on. write and evaluate an expression with exponents to find how many grains of rice the man puts on the tenth space.

If f(x)=2x-6 and g(x)=3x+9, find (f-g)(x)

The boiling point of water at an elevation of 0 feet is 212 degrees fahrenheit (°f). for every 1,000 feet of increase in elevation, the boiling point of water decreases by about 2°f. which of the following represents this relationship if b is the boiling point of water at an elevation of e thousand feet? a) e = 2b - 212 b) b = 2e - 212 c) e = -2b + 212 d) b = -2e + 212

Simplify (4x^2 - 8xy + 2y^2) - (9x^2 - 4xy - 7y^2) a. -5x^2 + 4xy + 9y^2 b. -5x^2 - 4xy + 9y^2 c. -5x^2 + 12xy + 4y^2 d. -5x^2 - 4xy - 5y^2