Please help me answer these

5,600 x 10^3 = a) 560 b) 5,000,600 c) 5,600,000 d) 56,000

If f(x)=2x-6 and g(x)=3x+9, find (f-g)(x)

Three people are traveling and need to exchange the currency of their native country for the currency of the country they are visiting. drag each exchange to the category that shows the ratio of currencies in that exchange.