请教一道高一数学题目，谢谢！

(lg5)^2 + (2/3)*lg8 + lg5*lg20 + (lg2)^2
=(lg5)^2 + 2*lg2 + lg5*（lg5+2lg2) + (lg2)^2
=[(lg5)^2+2lg2lg5+(lg2)^2]+2lg2+(lg5)^2
=(lg5+lg2)^2+2lg2+(lg5)^2
=1+2lg2+(lg5)^2
如果不是你的题目错，那就是你的答案错

题目写错了

请问^是什么

(lg5)^2 + (2/3)*lg8 + lg5*lg20 + (lg2)^2
=lg5*lg5+lg5*lg20+2lg2+(lg2)^2
=lg5(lg5+lg20)+lg2(2+lg2)
=lg5*lg100+lg2(2+lg2)
=2lg5+2lg2+(lg2)^2
=2(lg5+lg2)+(lg2)^2
=2+(lg2)^2

(lg5)^2 + (2/3)*lg8 + lg5*lg20 + (lg2)^2
=(lg5)^2 + 2lg2 + lg5(2lg2+lg5 )+ (lg2)^2
=[(lg5)^2 + 2lg2lg5+ (lg2)^2]+2lg2+lg5lg5
=[lg5+lg2]^2+2lg2+(1-lg2)^2
=1+1+(lg2)^2
=2+(lg2)^2