Answer:
37 units
Step-by-step explanation:

Using the distance formula above,
distance between (15, -17) and (-20, -5)
![= \sqrt{[15 - ( - 20)]^{2} + [ - 17 - ( - 5)] {}^{2} } \\ = \sqrt{(15 + 20)^{2} + ( - 17 + 5)^{2} } \\ = \sqrt{35 ^{2} + ( - 12) {}^{2} } \\ = \sqrt{1225 + 144} \\ = \sqrt{1369} \\ = 37 \: units](https://tex.z-dn.net/?f=%20%3D%20%20%5Csqrt%7B%5B15%20-%20%28%20-%2020%29%5D%5E%7B2%7D%20%20%2B%20%5B%20-%2017%20-%20%28%20-%205%29%5D%20%7B%7D%5E%7B2%7D%20%7D%20%20%5C%5C%20%20%3D%20%20%5Csqrt%7B%2815%20%2B%2020%29%5E%7B2%7D%20%2B%20%28%20-%2017%20%2B%205%29%5E%7B2%7D%20%20%7D%20%20%5C%5C%20%20%3D%20%20%5Csqrt%7B35%20%5E%7B2%7D%20%2B%20%28%20-%2012%29%20%7B%7D%5E%7B2%7D%20%20%7D%20%20%5C%5C%20%20%3D%20%20%5Csqrt%7B1225%20%2B%20144%7D%20%20%5C%5C%20%20%3D%20%20%5Csqrt%7B1369%7D%20%20%5C%5C%20%20%3D%2037%20%5C%3A%20units)
Part I)
The module of vector AB is given by:
lABl = root ((- 3) ^ 2 + (4) ^ 2)
lABl = root (9 + 16)
lABl = root (25)
lABl = 5
Part (ii)
The module of the EF vector is given by:
lEFl = root ((5) ^ 2 + (e) ^ 2)
We have to:
lEFl = 3lABl
Thus:
root ((5) ^ 2 + (e) ^ 2) = 3 * (5)
root ((5) ^ 2 + (e) ^ 2) = 15
Clearing e have:
(5) ^ 2 + (e) ^ 2 = 15 ^ 2
(e) ^ 2 = 15 ^ 2 - 5 ^ 2
e = root (200)
e = root (2 * 100)
e = 10 * root (2)
It's called a decimal.
I hope it helps.
Six hundred seventy-two thousandths <0.8
Answer:

Step-by-step explanation:
