x^2+(x+1)^2+(x+2)^2=302
x^2+x^2+2x+1+x^2+4x+4=302
x^2+x^2+x^2+4x+2x+1+4=302
3x^2+6x+5=302
3x^2+6x-297=0
x^2+2x-99=0
d=4-4*1*(-99)=400
x1=20-2/2=9
x2=20+2/2=11
pervaja cisla eto 9,vtaraja 11 i naidem tretiju
9^2+11^2+x^2=302
202+x^2=302
x^2=302-202=100
x=10
Otvet:9,10,11