-16F temperature change divided by 4 hour difference from 8 to 12/noon.
-16 divided by 4 = -4
The answer is -4 degrees Fahrenheit.
Compute the differential for both sides:
4<em>y</em> - 3<em>xy</em> + 8<em>x</em> = 0
→ 4 d<em>y</em> - 3 (<em>y</em> d<em>x</em> + <em>x</em> d<em>y</em>) + 8 d<em>x</em> = 0
Solve for d<em>y</em> :
4 d<em>y</em> - 3<em>y</em> d<em>x</em> - 3<em>x</em> d<em>y</em> + 8 d<em>x</em> = 0
(4 - 3<em>x</em>) d<em>y</em> + (8 - 3<em>y</em>) d<em>x</em> = 0
When <em>x</em> = 0, we have
4<em>y</em> - 3•0<em>y</em> + 8•0 = 0 → 4<em>y</em> = 0 → <em>y</em> = 0
and with d<em>x</em> = 0.05, we get
(4 - 3•0) d<em>y</em> + (8 - 3•0) • 0.05 = 0
→ 4 d<em>y</em> + 0.4 = 0
→ 4 d<em>y</em> = -0.4
→ d<em>y</em> = -0.1
Answer:
They sold 120 milkshakes that day
Step-by-step explanation:
We can set up a proportion
Note: If you have some value, 
, and it is 
of the total amount, you can find the value by doing the equation 
30.13 is the correct answer
