Answer:
the first equation could be something along the lines of 
then the second is 
Step-by-step explanation:
this is how shifting works
Answer:
7k
Step-by-step explanation:
−k−(−8k) = -k +8k = 7k
Answer:
False
Step-by-step explanation:
Answered it on E2020
Remark
You are dealing with a right angle triangle. You can use one of Sin(x) Cos(x) or Tan(x). Since the Hypotenuse is involved and since you are given the adjacent side, Cos(71) is what you will need.
Solution
H = BC
Cos(x) = adjactent / hypotenuse
Cos(71) = 6.3 / H Multiply both sides by H
H * Cos(71) = 6.3 Divide by Cos(71)
H = 6.3 / cos(71) Cos(71) = 0.32557
H = 6.3 / 0.32557 Divide
H = BC = 19.351 Answer
