How to combine multiple linear equations or curves?

Question

For example, The first equation contains variables 'a' and 'b', Second 'a' and 'c', Third 'a' and 'd', and so on. So If i want to get an equation with 'a' and b,c,d,... (That means 'a' on x-axis and b,c,d,e,... on y-axis). Is there any software which can solve this problem?

Thank you Dutch prof for the answer. But I have obtained equations from Excel And I have the equations as
a=(function of b)
a=(function of c)
a=(function of d)
and so on.
And Now i want an equation in the form of
a = f{a,b,c,d.....}

Answer 1

you have
a=a eq(1)
a=f(b), eq(2)
a=f(c),.... eq(3) and so on.

Add all the equations to get:
n.a= a+f(b)+f(c)+........ up to n-terms
where n=number of equations.

so now, a=[a+f(b)+f(c)+.......]/n
which is of form a=F(a,b,c,d,.......).

Answer 2

If your equations are in the form
b = ... (formula with a) ...
c = ... (formula with a) ...
and so on, use any program that can plot graphs. Microsoft Excel will work, if you enter values for a in the left column, the formulas for b, c, etc. in the next columns; select them, click the Graph icon and choose XY Scatterplot with connected lines.

Answer 3

please i would like to know.