How to represent an expression as a decimal?

Question

MATLAB

I have some matrix W, and when I perform the inverse Laplace transform using the ilaplas function, I get an expression like this:

6*exp(-(7*t)/2)*(cosh((21^(1/2)*t)/2) - (5*21^(1/2)*sinh((21^(1/2)*t)/2))/21)

Please tell me how to remove rational fractions and convert all numerical values ​​to decimal form, for example, 0.5 instead of 1\2, etc.