64 =4*4*4=4³
log9 log4 16 =log9 3=1/2
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log9 16 - log27 8 =log3² 4² - log3³ 2³ =log3 4 -log3 2 =log3 (4/2) =log3 2
3^ (log3 2)=2^(log3 3) =2
<span>х+у=4 ; x = 4 - y
подставляем
(4-y) -4y =3
4-y -4y = 3
5y =1
y = 1/5
подставляем
</span>x = 4 - 1/5 = 19/5
ответ
(19/5 ; 1/5)
Х + 5у = 2( Х + у )
Ху - у = 10
Решение
Х + 5у = 2х + 2у
2х - Х = 5у - 2у
Х = 3у
у•3у - у = 10
3у^2 - у - 10 = 0
D = 1 + 120 = 121 = 11^2
y1 = ( 1 + 11 ) : 6 = 2
y2 = ( 1 - 11 ) : 6 = - 5/3 = - 1 2/3
X1 = 3•2 = 6
X2 = 3•( - 5/3 ) = - 5
Ответ ( 6 ; 2 ) ; ( - 5 ; - 1 2/3 )
2а^2b^3=-3. a^2b^3=-3/2
2a^4b^6=4,5 2a^4b^6=2(a^2b^3)^2=2×(3/2)^2=2×9/4=9/2===4,5