0.345²+1.345²-0.345×2.69
=0.345²+(1+0.345)²-0.345×2.69
=0.345²+0.345²+2×0.345+1-0.345×2.69
=0.345(0.345+0.345+2-2.69)+1
=0+1
=1
0.345²+1.345²-0.345×2.69
=0.345²+(1+0.345)²-0.345×2.69
=0.345²+0.345²+2×0.345+1-0.345×2.69
=0.345(0.345+0.345+2-2.69)+1
=0+1
=1