求这两题的计算过程,详细一点。不能跳太快,还有就是能不能在纸上写呢,可以看清楚点,谢谢了!

2025-06-28 11:03:55
推荐回答(1个)
回答1:

原式
=-2lg10+lg5*lg(5*4)+lg2*lg2

=-2+lg5*(lg5+lg4)+lg2*lg2
=-2+lg5*lg5+lg5*lg4+lg2*lg2
=-2+lg5*lg5+lg5*(lg2+lg2)+lg2*lg2

=-2+lg5*lg5+lg5*lg2+lg5*lg2+lg2*lg2
=-2+lg5*(lg5+lg2)+lg2(lg5+lg2)
=-2+lg5+lg2
=-2+lg10
=-2+1
=-1

(2)3^a=2 log3 8-2log3 6
log32=a

log3 8-log3 36
=log3 (8/36)
=log3 (2/9)
=log3 2-log3 9
=log3 2-2
=a-2