Hi, I am beginner in mathematics , I have the following three relationships:
I need to calculate c under the assumption that a, b and d are known values.
I got c=a-b+d
can I use any other formulas?!!
c=a/b*d is not true.
Unless you mean
That is generally not true but given your conditions...
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.