Penyelesaian A
1.
√18 -
√32 + √50 + √72 = 3√2 – 4√2 + 5√2 + 6√2 = 10√2 (A)
2.
p + 1
= x → p = x
– 1
4(x – 1)2 – 2(x – 1)
– 3 = 0
4x2 – 8x + 4 – 2x +
2 – 3 = 0
4x2 – 10x + 3 = 0 (C)
3.
(– 8)2
– 4(m – 1)(8m) ≥ 0
64 – 32m2 + 32m ≥ 0
m2 – m – 2 ≤ 0
(m – 2)(m + 1) ≤ 0
m = 2 atau m = – 1
– 1 ≤ m ≤ 2 (C)
4.
y =
a(x – 3)2 – 2
f(0) = 16→ 16 = a(9) – 2
a = 2
y = 2(x – 3)2 – 2 =
2x2 – 12x + 16 (D)
5.
Semua
peserta Ujian Nasional berdoa sebelum mengerjakan soal (E)
6.
p → ~q ≡ p → ~q
~r → q ≡ ~q → r
~ r r
~ p (A)
7.
x+
y + z = 12 3x + 2y – z = 8
2x – y + 2z = 12 2x + 2y +2z = 24
3x + 3z = 24 x
– 3z = – 16
3x + 3z
= 24
x – 3z
= – 16
x
= 2 → z = 6
→ y = 4
x.y.z = 2.4.6 = 48 (B)
8.
2 cos (2x + 1500)
= Ö3
cos (2x + 1500) = ½V3
cos (2x + 1500) = cos 300
1.
2x + 1500 = 300 + k.3600 2. 2x
+ 1500 = – 300 + k.3600
2x = – 1200 + k.3600 2x = – 1800 + k.3600
x = – 600 + k.1800 x = – 900 + k.1800
HP= {900,
1200} (B)

9.
Panjang vertikal = 10 tan 300 = 10/3 V3
Sudut puncak kelapa = 45o
(10/3 V3) : sin 450 = x
: sin 1200
10.V3.V3 = 3.x.V2
x = 5√2 (D)
10.
Jarak C ke BDG = 1/3 diagonal ruang = 3 cm (D)
11.
TP = CP =
= 2


Sudut ADB dengan ABC adalah sudut CED = α
Cos α =
= 


Tan α = 2√2
12.
5.4.7.6.5 = 4200
13.
1 3 3 1
Paling sedikit dua gambar = 4/8 = ½ (E)
14.
300000 = 

300 p + 300w = 320p + 285w
15w = 20p
3w = 4p
p : w = 3 : 4 (D)
15.
Mo = 85,5 +
= 85,5 + 3
= 88,5 (B)

16.
Tan 1050
= Tan (60 + 45)0
=
. 


= 

= – 2 –
(B)

17.
Cos 3x + Cos x = 2 Cos 2x cos x = 2 (1 – 2 sin2x)
Cos x = 2 (1 – 2.16/25).3/5 = - 42/125 (C)
18.
(x + 1)2
+ (y – 3)2 = 1
x2 + y2 + 2x – 6y + 9 =0 (D)
19.
3x – y + (x + 3) – 2(y – 1) – 20
= 0
4x – 3y – 15 = 0 (A)
20.
x4 – 3x3 – 5x2 + x – 6 = (x2 + bx + c)(x2 –
x – 2) + (px + q)
=
x4 – x3 – 2x2 + bx3 – bx2
– 2bx + cx2 – cx – 2c + px + q
= x4 – (1 – b)x3 – (2 + b
– c)x2 – (2b + c – p)x – 2c + q
1 – b = 3 2 + b – c = 5 p – c – 2b = 1 q – 2c = – 6
b = – 2 c = – 5 p = – 8 q = – 16
jadi sisanya : – 8 x – 16 (D)
21.
2a + b =8
– 3a + b = – 7
5a = 15
a = 3
b = 2
jadi didanya : 3x + 2 (E)
22.
6(5p + 4) – 3 = 81
30p + 24 = 84
p = 2 (D)
23.
5yx + 3y = 2x – 1
2x – 5yx = 3y + 1
x =
=
, jadi a = –3 dan b = 5 maka 2a + b = – 6 + 5 = – 1
( A)


24.
=


=

= 6
(B)
25.
=
=
( C )



26.
f(x) = cos5
(4x – 2)
f’(x) = 5cos4(4x – 2).sin (4x – 2)(– 4) = – 10 cos3 (4x – 2) sin (8x – 4). (E)
27.
L = a2 + 4at = 108
V= a2t = a2(108 – a2)/4a = 27a – a3/4
V’ = 27 – ¾ a2 = 0
27 = ¾ a2
a2 = 4.9
a = 6
(A)
28.
y = x3 – 3x2 + x + C
– 3 = 8 – 12 + 2 + C
C = – 1
Jadi persamaan kurva itu :y = x3 – 3x2 + x – 1 ( B )
29. ò sin5
x. cos x dx = ò sin5
x d(sin x) = 1/6 sin6 x +
C (A)
30. V
= π
= π{(
+ 16 + 18)} = 40
π (A)



31. 102 + 105 + 108 + ... + 399
399 = 102 + (n – 1)3
297 = (n – 1)3
99 = n – 1
n = 100
Sn = 50.501 = 25.050 (C)
32. ar5 : ar2 = 10 2/3 :
36
r3 = 8/27
r = 2/3
a = 9.9
S~ = 9.9/(1 – 2/3) = 9.9.3 =
243 (B)
33.
Titik
|
A
|
B
|
C
|
Koordinat
|
(30,0)
|
(0,63)
|
(8,55)
|
500x + 300y
|
15.000.000
|
18.900.000
|
4.000.000+16.500.000 =20.500.000
|
34. 3 = 2 + 2p → p = ½
5 = q + 4 → q = 1
p + q` = 3/2 (A)
35. 6 – 4 – 2x = 0 → x = 1 (E)
36. Proyeksi
vektor ortogonal
pada
= (4 +
8 – 24)/24 {2
– 2
+ 4
}





= –
+
- 2



37. rotasi
dengan pusat (0,0) sejauh +90o →
y = – x’ dan x = y’
x
– 2y + 4 = 0 →
y’ + 2x’ + 4 = 0
pencerminan terhadap garis y = x →
y’ = x’’ dan x’ = y’’
x’’ + 2y’’
+ 4 = 0
Jadi bayangannya adalah x + 2y + 4 = 0
38. Lbayangan = ½ .6.4 = 12
39. 5log(x2 – 7x – 1) – 5log (4 – 3x) = 0
x2 – 7x – 1 = 4 –
3x
x2 – 4x – 5 = 0
(x – 5)(x + 1) = 0
x = 5 (tm) atau x = – 1 (D )
40. 32x+1
–10.3x + 3 = 0, diketahui
akar- akarnya adalah x1
dan x2 dimana x1 < x2.
Nilai dari 2x1 – 3x2
3a2 – 10a + 3 = 0
(3a – 1)(a – 3) = 0
a = 1/3 atau a = 3
x = – 1 atau x = 1
2x1 – 3x2 = – 2 – 3 = – 5