Answer:
Step-by-step explanation:6/5
A+bi is the form of a complex number. a is on the x axis, bi is on the y axis:
3-4i ( x positive, y negative) Q4
-1-3i (both x, y negative) Q3
4+i ( both x, y positive) Q1
-2+2i (x neg, y pos) Q3
We're given that 
and 
, and want to find 
.
By the chain rule, we have
and
Then
(because the point 
corresponds to 
)
For the first one it’s h=6 and the second one is h=-3
Answer:
$2.72
Step-by-step explanation:
The increase from last week is the fraction ...
(new price)/(old price) -1 = (1.82/1.65) -1 = 17/165
so the amount of increase Sally will pay this week is ...
17/165×$26.40 = $2.72
_____
<em>Comment on the working</em>
We could work this several ways. Perhaps most straightforward would be to determine how many gallons Sally bought last week, and multiply that by the change in price. Or, the number of gallons could be multiplied by the new price per gallon and the difference from the old purchase amount found.
If you look at the numbers, you see that we have effectively done it the first way. The change in price is $0.17 per gallon, and the number of gallons Sally bought is $26.40/$1.65.
