Page 41 - Spotlight A+ Form 4 & 5 Mathematics KSSM

Answers

1. y 9. a = –1  0
Shape
2
f(x) = 0, 3x – x = 0
x(3 – x) = 0
x = 0 or x = 3
(0, 9) y

x
O
Answer: D
2. Answer: C O 3 x
2
3. (x + 10) + (x + 5) = 25 2
2
2
2
x + 20x + 100 + x + 10x + 25 = 625
2x + 30x – 500 = 0
2
x + 15x – 250 = 0 Answer: A
2
Answer: A 10. y = a(x + 4)(x – 1)
2
2
4. x + 3 = 4 = ax + 3ax – 4a
2
a = 1, y = x + 3x – 4
x
2
The power of x is –1. a = 2, y = 2x + 6x – 8
2
Answer: C a = 3, y = 3x + 9x – 12
Answer: D
2
5. x = 4, a(4) + 14(4) – 8 = 0
16a + 56 – 8 = 0 11. y
16a = –48
y = (x + 3)
2
2
y = (x – 1)
a = –3
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Answer: B
6. 2x – 13x + 15 = 0 1
2
(2x – 3)(x – 5) = 0 x
2x – 3 = 0 or x – 5 = 0 –3 –1 O 1
3
x = or x = 5 –2 2
2
Answer: A y = (x – 1) – 2
7. (y + 3) = 4
2
2
y + 6y + 9 = 4 12. (a) y
2
y + 6y + 5 = 0
(y + 1)(y + 5) = 0 16
y = –1 or y = –5 y = –x + 16
2
Answer: B
8. x + 8x + 16 = 0
2
(x + 4) = 0 O x
2
x = –4 or x = –4 (same sign) –4 4
x + 7x + 6 = 0
2
(x + 1)(x + 6) = 0 (b) y
x = –1 or x = –6 (same sign) 2
x – 2x – 8 = 0 y = x + 5x
2
(x + 2)(x – 4) = 0
x = –2 or x = 4 (different sign)
x – 11x + 24 = 0 x
2
(x – 3)(x – 8) = 0 –5 O
x = 3 or x = 8 (same sign)
Answer: C
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