See the following

quadratic solver.sm (6 KiB) downloaded 63 time(s).


Note how second root from solve function generated a fraction containing
large numbers with minor error. This compares with actual which is a
simplistic decimal.

Is there a work-around to obtain the correct decimal result?

Your fractional didn't survive as soon as I asked
for 15 decimals in your 'r1'.

quadratic solver.sm (8 KiB) downloaded 73 time(s).

Simply change the optimization of [MATH]solve(f(x),x)[/MATH] from symbolic to numeric.