1.a. t(t+10)
1.b. 15cm

2.a. (2x+1)(x-3)
2.b. 2x^2-5x-18=0
2.c. 1.5 cm

3. 2 and 3 or -2 and -3

4. 5 and 6

5.  14cm by 22.5 cm

6. 79.3 cm and 20.7 cm

7. Harun's speed = 28.5km/h, Fairuz's speed = 19.5 km/h

8.a. -24
8.b. 8

9. p=1, q=-20