1.вычислить: log3 4 - log3 16 + log3 4/9; 2. вычислить: 2 log7 27 – log7 81-2 log7 21 3. вычислить: 2 log2 8 +log2 15/4 – log2 15 4. log3 7 * log4 81 * log7 2 5. вычислить: lg3(log325+log32 - log35)
Ответы на вопрос:
1) log3 4 - log3 16 + log3 4/9= log3 4/ 16 + log3 4/9=log3 ((4/16)*( 4/9))= log3 1/9=
log3 (3)^-2= -2
2) 2 log7 27 – log7 81-2 log7 21=log7 27^2 / 81-2 log7 21= log7 729/ 81- log7 21 ^2= log7 9- log7 21 ^2 = log7 (9/ 441)= log7 (1/ 49) = log7 (7^-2)=-2
3) 2 log2 8 +log2 15/4 – log2 15=log2 (8^2*(15/4)) – log2 15= log2 ((64*15)/4) – log2 15 =
log2 (16*15) – log2 15 = log2 ((16*15)/15)= log2 (16)= log2 (2^4)=4
4) log3 7 * log4 81 * log7 2= log4 81 * log7 2*1/ log7 3= log4 3^4 *( log7 2/ log7 3 )=
4* log4 3 * log3 2=4* log3 2*(1/ log3 4) = 4* log3 2*(1/ log3 2^2) = 4* log3 2*(1/ 2 log3 2)= (4* log3 2)/ (2 log3 2) =4/2=2
5) lg3(log3 25+log3 2-log3 5) = lg3(log3 (25* 2)-log3 5)= lg3(log3 50/ 5) = lg3*log3 10 = log10 3* log3 10= log10 3/ log10 3=1
1. log3 1/4 +log3 4/9= -2
2.log7 (729/{441*81}) = -2
3.log2 240-log2 15 = 4
4.(log7 2 / log7 3) *1/2log2 81 = 1/2 * (log2 81/log2 3) = 2
Популярно: Алгебра
-
EgotinSmey26.09.2020 19:41
-
829ld4b23.07.2020 06:24
-
андрей204820.07.2021 17:38
-
AndaDi08.05.2020 11:56
-
николаj16.04.2023 20:38
-
chucklplplplpl09.07.2022 20:58
-
Dintyukld31.01.2023 02:24
-
adaman200602.11.2020 18:37
-
anitabadurova04.10.2021 17:44
-
austimenko29121.06.2021 23:30