Answer:
(-6, -3)
Step-by-step explanation:
The coordinate is at (2, -1), when using a dilation with a scale factor of 3, multiply the coordinates by 3.
(2, -1) ------> (2 x 3, -1 x 3) ----------> (6, -3)
When reflecting the point over the y-axis, take the opposite of the x coordinate.
(6, -3) ------> (-6, -3)
Given two points. we can find the equation of a line passing through the points
The formula to be used is:
where
=>
The next step is to cross multiply
=>
Divide both sides by 6 and make x the subject
x=3
The double angle identities are
Then
The second identity together with the Pythagorean identity, 
, gives us another equivalent expression:
so
Answer:
3hrs 12 mins
Step-by-step explanation:
For every 10% charge she gets 1hr 20mins (or 80 mins)
Charge drop = (81% - 57%) = 24%
Since 10% gives 80 mins;
24% gives (24/10) x 80 mins = 192 mins
since 1hr = 60 mins
192 mins = 192/60 = 3hrs 12 mins
