Get an expression from two equations

[finance.addict]

How do I get :

n1 = Vi(Di - D3) / B1(D1 - D3) from these two equations :

1. Vi = n1 x b1 x n3 x b3

2. Di = ((n1 x b1 x D1) / Vi) + (n3 x b3 x D3) / Vi

Thanks in advance

 

[Deleted member 4993]

How do I get :

n1 = Vi(Di - D3) / B1(D1 - D3) from these two equations :

1. Vi = n1 x b1 x n3 x b3

2. Di = ((n1 x b1 x D1) / Vi) + (n3 x b3 x D3) / Vi

Thanks in advance

Replace V_i in (2) using (1)

If you are still stuck, post back showing your 'work' and pointing out exactly where you are stuck.

 

[Dr.Peterson]

How do I get :

n1 = Vi(Di - D3) / B1(D1 - D3) from these two equations :

1. Vi = n1 x b1 x n3 x b3

2. Di = ((n1 x b1 x D1) / Vi) + (n3 x b3 x D3) / Vi

Thanks in advance

Are [MATH]B_1[/MATH] and [MATH]b_1[/MATH] supposed to be the same?

As I understand it, you know that [MATH]V_i=n_1b_1n_3b_3[/MATH] and [MATH]D_i=\frac{n_1b_1D_1+n_3b_3D_3}{V_i}[/MATH], and want to solve for [MATH]n_1[/MATH], eliminating [MATH]n_3[/MATH] and [MATH]b_3[/MATH] together.

That can be done since they only appear together. Solve your first equation for[MATH]n_3b_3[/MATH], and put that into the second equation. But I don't think that will get the equation you want.

Is there any more you can tell us?