[poca]

I did
ka=3x10^-2 = [H3o][H2PO3] / [H3PO3] so  x^2 / .4 - x = 3x10^-2
I made that into a quadratic and solved it.
for x = h30 = .1152
pH= -log .1152
pH=.939

[Borek]

1^st dissociation constant for phosphoric acid is not 0.03. But even if it was, 0.1152M would be not correct solution of the quadratic.

x^2 / .4 - x = 3x10^-2

There are no parentheses in the denominator, so what you wrote is ambiguous. There are chances it is a correct approach.

[AWK]

Many sources give Ka for phosphorous acid (H3PO3) as 0.03.

Check your calculations with web pH calculator eg: http://www.webqc.org/phsolver.php

[poca]

ok,  (x^2) / (.4-x) = .03
quadratic is x^2 + .03x - .012
x = .095566
pH = 1.0197

[Borek]

Much better now.

I would report as 1.02, and even that would be way too many digits.