I noted in my self-introduction post that I forgot much of my maths knowledge way back in the last century, so please forgive me if this is a somewhat basic query. It's based on a real-life problem that I'm trying to resolve.

I have a line with four points on it - A at the beginning, D at the end, and B & C in between. The positions of A, B & C are fixed; D is variable. The relationship between the four points is defined by two formulae:

C - D > x(B - C)

C > 0.5(A - D)

How do I find the minimum value of D, expressed in terms of A, B, C and x? D > . . . . . . . ??

In reality, 'x' is a variable factor. I need to find the minimum value of D using various factors, for example what it was 1.9(B - C), or 2.4(B - C).

Once some kind soul helps me with the expression for determining D then I'll drop it in an Excel spreadsheet and test for the minimum D value using different factors.

Assistance with this will be much appreciated.