2【lg5】^2+2lg2•lg50=?
问题描述:
2【lg5】^2+2lg2•lg50=?
答
解
2(lg5)²+2lg2lg50
=2(lg5)²+2lg2(lg5+1)
=2(lg5)²+2lg2lg5+2lg2
=2lg5(lg5+lg2)+2lg2
=2lg5lg10+2lg2
=2lg5+2lg2
=2(lg5×2)
=2