Why do I get a fraction instead of a rational number when I solve two simple simultaneous equations

These are the two equations I need to solve; for A and B, to calculate the viscosity of hydraulic fluid between to temperatures. The results are correct, but why does Matlab show them as fractions and not rational numbers?

syms A B

eqn1=A-520*B==3.7612;

eqn3=A-560*B==2.3026;

[X,Y] = equationsToMatrix([eqn1, eqn3], [A, B])
Z = linsolve(X,Y)

Z =

    22723/1000
   7293/200000

>> 22723/1000

ans =

     22.7230

>>  7293/200000

ans =

      0.0365

Answer 1

[John D'Errico]

Because you are (for some irrational reason) using symbolic computations to solve a simple linear system of equations. Sort of equivalent to the use of a Mack truck to bring a single pea to Boston - massive overkill. Therefore the result is a symbolic one, and is left in symbolic form.

If you want to convert it to a floating point number, then use vpa, or use double.

[Ali Kemal YELTER]

Hello. I am experiencing the same thing however I am solving a system with many unknowns. Is there a way i can make MATLAB show me the "double" results rathen than the fractional form?

[Steven Lord]

If the expressions contain symbolic variables use vpa to display the approximation of the symbolic result to a specified number of decimal places.

If the expressions are symbolic representations of numbers (no symbolic variables) use double.

sqrt5 = sqrt(sym(5))

sqrt5 = 

double(sqrt5)

ans = 2.2361

syms x
xsqrt5 = x*sqrt5

xsqrt5 = 

vpa(xsqrt5)

ans = 

Calling double on xsqrt5 won't work because of the presence of the x in the expression.

double(xsqrt5)

Error using symengine
Unable to convert expression containing symbolic variables into double array. Apply 'subs' function first to substitute values for variables.

Error in sym/double (line 702)
Xstr = mupadmex('symobj::double', S.s, 0);

[Ali Kemal YELTER]

Thank you for taking the time. ♥

Answer 2

[Walter Roberson]

https://www.mathworks.com/help/symbolic/sympref.html#mw_1464af98-5a29-4ac0-b0a7-3d101ea82566

Use sympref to set symbolic output to floating-point.

[Ali Kemal YELTER]

Thank you sir.