Formula to increase and decrease amount by a percentage found in other cells

I'm trying to create a formula that will reduce and increase a cell value by percentages found in other cells and finding it difficult so hoping someone can help with what i'm trying to do.

I've attached a sample sheet below with comments with what i am trying to achieve, probably super easy but my brain is fried!

if you need any other info please let me know and I'll do my best to provide.

https://docs.google.com/spreadsheets/d/1b-nhNYoamsMr2vFW1YZQvLXLuSksH83iW1weHtDDe3Q/edit#gid=2100307022

Thanks in advance