How do i find tyhe height of an area?

How do u write a function for the reflection across the y axis

The product of (7x-2) and (20-3x)/4. when x=4

Franklin is purchasing a home for $82,107 and is financing 80% of it. the documentary stamp tax on the deed in his state is $0.70 per $100 or portion thereof. how much will he pay for the documentary stamp tax?