How to equate two equations and find one of the unknown from it as a function of second unknown?

I have two equations,

R1 = 1.5;

ntone = R1 + etplusone + et; %%Equation(1)

nttwo = log(R1) + 2*etplusone + et^2; %%Equation(2)

%%% Please note, et and etplusone are the unknowns here

I wanted to equate these two equations and obtain etplusone as a function of et

Kindly help or advice on this, please.

Answer 1

[Paul]

syms et etplusone
R1 = 1.5;
ntone = R1 + etplusone + et;   %%Equation(1)
nttwo = log(R1) + 2*etplusone + et^2;  %%Equation(2)
soletplusone = solve(ntone == nttwo,etplusone,'ReturnConditions',true)

soletplusone = struct with fields:
     etplusone: - et^2 + et + 4929346931268077/4503599627370496
    parameters: [1×0 sym]
    conditions: symtrue

Seems like this would be straightforward to do by hand, wouldn't it?

[Kelvin Anto]

Hi Paul, Thank you for your answer. Yeah my question is actually complicated that this, but I just put an example to see the procedure.

Answer 2

[Voss]

A little bit of algebra gives:

etplusone = - et^2 + et + R1 - log(R1);