Can you tell me, if you have a regression equation with two partial regression coefficients (slopes), can you guestimate the p-values for each coefficient?

The regression equation we were given is:
y = 24.38 + 0.51 * x – 1.07 * x2

I suppose you could guestimate, but p-values for these coefficitents can be calculated exactly. Typically regression software will calculate a p-value for each coefficient automatically.