how to create multiple formula in one colum matrix

Hi, I'm new using Power BI, and I'm very confused to create column Matrix like this, 

so the value in column 32 is a (from colum 31)-b(from colum 31)+c(from column 31), column 33 is a (from the results of calculation 32)-b+c.
Please help, how do I create this visualization?
Thank You