let a,b and c be rational numbers and b=0.24-0.26a,c=0.26-0.24a,then a^2-b^2+c^2=
问题描述：
let a,b and c be rational numbers and b=0.24-0.26a,c=0.26-0.24a,then a^2-b^2+c^2=
答
a,b,c都是有理数,b=0.24-0.26a,c=0.26-0.24a,a^2+c^2-b^2=a^2+(0.5-0.5a)(0.02+0.02a)=0.99a^2+0,01