Answer:
a) 1200
b) 75
Step-by-step explanation:
By the chain rule,
where 
.
We have component partial derivatives
Putting the appropriate pieces together and setting 
, we get
A) y= (-1/2)x+50
(y=(-1/2)4 +50 = -2+50= 48)
Y=( -1/2 )8-50=-4+50 =46
B) -1/2X+50>=40
-1/2X>= -10
X<=20
To start the meeting with 40 students it should be 20 minutes or less before the meeting
Draw the line with the zero in the middle
Draw a closed circle at +20 and from that point draw a line to the left
Answer: 2 hr.
Explanation: Think back to rate of change. <em>d</em> = <em>rt</em>, <em>r</em> = <em>d/t</em>, <em>t</em> = <em>d/r</em>. In this case, we will be using <em>d</em> = <em>rt</em>. Mph would be <em>r</em>, rate, so you would categorize 15 mph and 8 mph under rate. <em>t</em> should represent the time each cyclist traveled. Tracey's and Emma's distance, <em>d</em>, would be the same as their mph, hence Tracey's being 15<em>t</em> and Emma's would be 8<em>t</em>. When you add Tracey's distance plus Emma's distance, you end up with 46 mi. Now, you need to combine like terms, which should look like 15<em>t</em> + 8<em>t </em> = 46. Add 15 and 8 to get 23, so it should be 23<em>t</em> = 46 now. Then, divide both sides of the equation by 23 and now you should have your answer, <em>t</em> = 2 hr.
Answer:
if your writiing it out then it's 3x + 20 = 32
