-(-9)=9 is true because a negative to a negative is positive
Answer:
33.8
Step-by-step explanation:
1) Use Phythagoras theorem to get RS ↓

2) RS = RQ
therefore, to get the perimeter, you'll have to total up the sides of the triangle ↓

Hope this helps =)
Answer:
y=29/4x
Step-by-step explanation:
Answer:
455.
Step-by-step explanation:
Yes. You require the number of combinations of 3 from 15.
15C3
The formula for this is 15! / 12! 3! or you can do itr as follows
15C3 = 15*14*13/3*2*1
= 5*7*13
= 35*13
= 455.