tolong kerjakan no. 5 dan 6 yah.. kalau bisa pakai cara cepat

Mapel : Matematika
Tingkat : SBMPTN
Bab : Aljabar dan Logaritma

Pembahasan :
5||

Misal 1/(x - 1) = a
1/(y + 2) = b

Jadi...
2a - b = 10
3b + a = -9 |x 2| 6b + 2a = -18

Eliminasi...
2a + 6b = -18
2a - b = 10
———————(-)
7b = -28
B = -4

Substitusi...
2a - b = 10
2a - (-4) = 10
2a = 6
a = 3

Maka...
1/(x - 1) = a
1/(x - 1) = 3
1 = 3x - 3
3x = 4
x = 4/3

1/(y + 2) = b
1/(y + 2) = -4
1 = -4y - 8
4y = -9
y = -9/4

Maka...
x + y
= 4/3 - (9/4)
= (16 - 27)/12
= -11/12

Opsi C.

6||

P'log 2 = 9
P^9 = 2

Q'log 4 = 8
Q^8 = 4
(Q²)^4 = 4
Q² = √2

s = p³
s³ = (p³)³
s³ = 2
s = ³√2

t = q²
t = √2

Maka...
t'log s
= √2'log ³√2
= 2^(1/2)'log 2^(1/3)
= (1/3)/(1/2) ²log 2
= 2/3

Opsi C.