Please help with this!

If the sales price of a dvd is $20 and the markup is 34%, what is the cost of the dvd?

The table below shows the approximate masses of a dust particle and a grain of pollen. dust particle 0.000000778 g grain of pollen 0.00000000155 g the mass of a dust particle can be estimated and written in the form a × 10^b, where a = 8 and b = the mass of a grain of pollen can be estimated and written in the form a × 10^b, where a = 2 and b = based on the estimates, the mass of a dust particle is approximately blank times larger than the mass of a grain of pollen.

Given: m zade = 60° and m2cdf = (3x + 15) prove: x = 15