HELP! Please and thanks

Will mark brainliest! ( explain the answer too, it can be one sentence)

What is the slope of the line that has an equation of y equals x -3

Acommunity group is building a garden on a rectangular lot of land. the lot measures 5x by 10x and the garden will be circular with a radius of 3x. how much of the land will be left over after the garden is built? a. 41 pi x^2 b. x^2 (50 - 9 pi) c. x^2 (50 - 3 pi) d. 41x^2