Need some not really sure where to start

The slope of a line is –2 and its y-intercept is (0, 3). what is the equation of the line that is parallel to the first line and passes through (2, 2)? a. 2x + y = 6 b. y = –2x + 3 c.y=1/2x +6 d.y=-2x-6

Kelly is a salesperson at a shoe store, where she must sell a pre-set number of pairs of shoes each month. at the end of each work day the number of pairs of shoes that she has left to sell that month is given by the equation s=300-15x , where s is the number of pair of shoes kelly still needs to sell and x is the number of days she has worked that month. what is the meaning of the number 300 in this equation

Afarm that has 4 x 10^2 acres has 1.2 x 10^5 cattle. what is the average number of cattle per acre? write the answer in scientific notation. answere asap