What is the definition of proof in geometry

Which value is not a solution of 8x^3 – 1 = 0

The following frequency table relates the weekly sales of bicycles at a given store over a 42-week period. value01234567frequency367108521(a) in how many weeks were at least 2 bikes sold? (b) in how many weeks were at least 5 bikes sold? (c) in how many weeks were an even number of bikes sold?

3x + 4y = 5 x- 3y = -7 solve by substitution