Ti-89 is a mysteri for me/ need help in solving algebric eqn

[grandure]

I have heard about TI-89 calculator a lot and i just borrowed my friend's calculator before i buy one, but i'm a bit frustrated when i couldn't figure out how to solve 5 variables in 2 equation (algebric equations) as the following example,

vx(1+1/s+s)+vy(s)-v2(s)-v1=0
vy(1/s+1/s+s)-vx(1/s)-v2(1/s)=0
v2(1+1/s+s)-vy(1/s)-vx(s)=0

the result that i'm looking for is v2/v1= (s^4+2s^2+1)/(2s^4+3s^3+6s^2+3s+2)

the above result is correct 100% i allied that manualy and with matlab software:)

I was thinking of using solve command in TI-89 but it showed and error says " too few argument".

I really your assistance.
looking forward.

[mellamokb]

You can solve multivariable equations by joining them with "and" in the solve command, and listing all of the variables to solve for in a {} list:

solve( (vx)(1+1/s+s)+(vy)(s)-(v2)(s)-v1=0 and (vy)(1/s+1/s+s)-(vx)(1/s)-(v2)(1/s)=0 and (v2)(1+1/s+s)-(vy)(1/s)-(vx)(s)=0, {v2,v1})

This will solve the three equations simultaneously and display the result in terms of the variables v1 and v2.

Note also that I put the terms vx, vy, and v2 in parentheses or else it will try to interpret vy(s) as a function application of vy on the input s, rather than vy*s.

Hope this helps!

Regards,
~ mellamokb