Answer:
Andrew's residence is higher
801 rounded to the nearest ten would be 811
Answer: see proof below
<u>Step-by-step explanation:</u>
Given: cos 330 = 
Use the Double-Angle Identity: cos 2A = 2 cos² A - 1

Proof LHS → RHS:
LHS cos 165
Double-Angle: cos (2 · 165) = 2 cos² 165 - 1
⇒ cos 330 = 2 cos² 165 - 1
⇒ 2 cos² 165 = cos 330 + 1
Given: 

Divide by 2: 

Square root: 
Scratchwork: 

Since cos 165 is in the 2nd Quadrant, the sign is NEGATIVE

LHS = RHS 
$639.20
She earns $5 an hour plus 4%
4% of 12,480 is $499.20
$5*28 hours is $140
$499.20 + $140 = $639.20
There are 24 students in the class