作业帮求值(log43+log83)(log32+log92) 注：log后面那为数是底数,最好用通俗易懂的解法.还有一题：lg14-2lg7/3+lg7-lg18
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求值(log43+log83)(log32+log92) 注：log后面那为数是底数,最好用通俗易懂的解法.还有一题：lg14-2lg7/3+lg7-lg18
求值(log43+log83)(log32+log92) 注：log后面那为数是底数,最好用通俗易懂的解法.
还有一题：lg14-2lg7/3+lg7-lg18
求值(log43+log83)(log32+log92) 注：log后面那为数是底数,最好用通俗易懂的解法.还有一题：lg14-2lg7/3+lg7-lg18
lg14-2lg7/3+lg7-lg18
=(lg2+lg7)-2(lg7-lg3)+lg7-(lg9+lg2)
=2lg3-lg9
=lg3²-lg9
=lg9-lg9
=0
⑴ 求值(log4↓3+log8↓3)(log3↓2+log9↓2) 注：log后面那为数是底数；
(log4↓3+log8↓3)(log3↓2+log9↓2
=(lg3/lg4+lg3/lg8)(lg2/lg3+lg2/lg9)
=lg2/lg4+lg2·lg3/lg4·lg9+lg2/lg8+lg2·lg3/lg8·lg9
=1/2+1/4+1...
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⑴ 求值(log4↓3+log8↓3)(log3↓2+log9↓2) 注：log后面那为数是底数；
(log4↓3+log8↓3)(log3↓2+log9↓2
=(lg3/lg4+lg3/lg8)(lg2/lg3+lg2/lg9)
=lg2/lg4+lg2·lg3/lg4·lg9+lg2/lg8+lg2·lg3/lg8·lg9
=1/2+1/4+1/3+1/6
=30/24
=5/4
⑵ lg14-2lg7/3+lg7-lg18
=lg(14÷49/9×7÷18)
=lg882/882
=lg1
=0
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