If the item was marked up by 1/2 before it was placed on the sales floor, what was the price that the store paid

If given an equation of a line such as -1/2x+6 how would you create an equation of a line parallel and perpendicula to this line that goes through another point such as (4,10)

Scott harris can invest $7,000 in a 1-year cd that earns interest at an annual rate of 4 percent compounded monthly. the amount per $1.00 is 1.040742. he can also invest $7,000 in a 1-year cd at annual rate of 4 percent compounded quarterly. the amount per $1.00 is 1.040604. what is the difference in the amount of interest earned for each investment? a) $0.96 b) $0.81 c) $0.87 d) $0.88

Guys i really need or i have to stay late up night