Answer:
Change in sulfur oxide in the air = 
Step-by-step explanation:
Data provided in the question:
Relation between the amount of sulfur oxide in the air and the population as:
S² = 110P² + 20P + 600
Population growth rate, 
= 10 people per month
Now,
change in sulfur oxide with time i.e 
differentiating the given relation with respect to time 't'
we have
= 
+ 20
at P = 100 and = 10 people per month
we have
= 2 × 110 × 100 × 10 + 20
or
= 220020
or
= 
or
Change in sulfur oxide in the air =
Answer:
The average speed of the car is 45.76 mph
Step-by-step explanation:
avg speed = distance / time
Answer:
Plan A last 0.75 hours or 45 minutes.
Plan B last 1.5 hours or 90 minutes.
Step-by-step explanation:
Let 
be the number of hours that the plan A last, an 
the number of hours of plan B. Then for the Wednesday you have:
And for the Thursday is:
Multiply the equation of Wednesday by -3:
Using the method of addition using this last equation and the equation of Thursday
Replacing the value of in one of the equations
Answer:
1234567891011121314151617181920
Step-by-step explanation:
Joan makes $275/week.
In addition to $275, she also makes 4 percent on sales over $1000.
So, 1250 - 1000 = 250.
Then 250(0.04) = 10.
Let t = amount of her paycheck for the week.
t = $275 + $10
t = $285
