Simple Algebra Question

[WombRaider]

This is for a MacroEcon question, but basically the equation is like this:

a = 4000 + 0.8b

I need it in:

a/b = no variables

I've simplified it to:

a/b = 4000 + 0.8b/b

I forget how to manipulate these equations. =\

 

[AmpedSilence]

with two variables you need two equations.

i.e. a = 4000 + 0.8b
and a = 2000 + 0.6b

solve by...
2000 + 0.6b = 4000 + 0.8b
-0.2b = 2000
b = -20000

sub b back into one of the equations...

does that help?

 

[TecHNooB]

Originally posted by: AmpedSilence
with two variables you need two equations.

i.e. a = 4000 + 0.8b
and a = 2000 + 0.6b

solve by...
2000 + 0.6b = 4000 + 0.8b
-0.2b = 2000
b = -20000

sub b back into one of the equations...

does that help?

What the crap did you do? O_O

 

[WombRaider]

so the single equation i have is already simplified? hmm, then i'm reading this question incorrectly then lol.

now that i looked at the problem again, i realized i read the question incorrectly. it wants the derivative of the equation, oops.

 

[TehJustinator]

Please tell me you know how to find that derivative of that equation.

 

[Indolent]

Originally posted by: TehJustinator

Originally posted by: AmpedSilence
with two variables you need two equations.

i.e. a = 4000 + 0.8b
and a = 2000 + 0.6b

solve by...
2000 + 0.6b = 4000 + 0.8b
-0.2b = 2000
b = -20000

sub b back into one of the equations...

does that help?

Um...wtf?

a = 4000 + 0.8b

b = (a - 4000) / 0.8

Plug that into a and solve from there. Then plug the solution for b back in to solve for a.
Please tell me you know how to find that derivative of that equation.

I'm confused as to what you're trying to do. He only was given one equation, you just restated it in terms of b. You can't solve that. He just needs it in terms of a/b=...

*edit* err, I guess he needs the derivative, so it's a completely different problem

 

[dighn]

you can't state that in the form of a/b = constant

 

[TehJustinator]

Yeah, I'm being retarded and forgot you need a system of equations. Lol, it's late and I've been doing projects all day.

Apparently I'm typoing like crazy too today. Blah, screw math...

 

[WombRaider]

Originally posted by: TehJustinator

Please tell me you know how to find that derivative of that equation.

It's been a year since I took Calc I, but I managed to figure it out.