9. -7/12
10. -2.75
11. 1.844
12. 4.539
Answer:

Step-by-step explanation:
distance between two points:

we have:

Answer:
60 cm²
Step-by-step explanation:
base = 10
Height = √13² - 5² = √144 = 12
area = 1/2BH = 1/2 * 10 * 12 = 60
N2+40-28=
Combine like terms
n2+40-28=n2+12
Factor out 2
n•2+12=2(n+6)
Therefore the answer is 2(n+6)