3. C 67.5 mi
4. A 65mi
5. B $270
Two solutions:
1. x =(100-√2160)/2=50-6√ 15 = 26.762
2. x =(100+√2160)/2=50+6√ 15 = 73.238
The answer is 73.33333333 (repeated). You can also write it as 73 or 73.3 with a line over the 3 (after the decimal point) to indicate it being repeated.
Subtraction, you’d -6 to the other side and m=-10
Dot product is
a*b = |a|*|b|*cosα.
In our case
u*u =|u|*|u|*cos 0
u*u =|u|*|u|
12=|u|²
|u|=√12=√(4*3)=2√3
Answer: <span>D. 2√3</span>