Question

No 55 dong thanks :)

Answer 1

Alog(b - 2) , alogb , alog(b + 4) => 3 barisan aritmatika
Rumus beda pada aritmatika
U2 - U1 = U3 - U2
U2 + U2 = U1 + U3
2U2 = U1 + U3

U1 + U2 + U3 = 2
U1 + U3 + U2 = 2
2U2 + U2 = 2
3U2 = 2
U2 = 2/3
alogb = 2/3

U1 + U3 = 2U2
alog(b - 2) + alog(b + 4) = 2 . alogb
alog(b - 2)(b + 4) = alogb^2
(b - 2)(b + 4) = b^2
b^2 + 2b - 8 = b^2
2b = 8
b = 4

alogb = 2/3
alog4 = 2/3
alog4 = aloga^(2/3)
4 = a^(2/3)
a = 4^(3/2) = (2^2(3/2)) = 2^3 = 8
a + b = 8 + 4 = 12