Answer:
Part A) 25
Part B) 225
Step-by-step explanation:
Part A
The slope of the graph gives us the mile per gallon of the car.
Recall that the slope of the graph is rise over run.

Therefore car gets 25 miles per gallon
Part B) Since we know the slope of the direct variation line, we substitute into y=kx to get:

To find the number of miles the car travels using 9 gallons, we substitute x=9 to get:

This gives us 225 miles
Answer:
80 adults must addent to make a complete $1,000
Step-by-step explanation:
You start with the students, $3 for each and 200 of them attend. 3x200=600 dollars in total. Then you would subtract 600 from 1,000. Next you will do the adults, 5x80=400 (The "leftover" cash) $5 for each times 80 adults will be $400 in total.
Answer:
Correct choice is B
Step-by-step explanation:
Let a, b, c and d be the trapezoid's sides lengths.
The perimeter of the trapezoid is the sum of all sides lengths, thus,

If each side length is increased by a factor 7, then new sides have lengths 7a, 7b, 7c and 7d. The perimeter of new trapezoid is

Use the distributive property for this expression:

Since
then

Answer: a - 4.512 hours
b - 1.94 hours
Step-by-step explanation:
Given,
a) A(t) = 10 (0.7)^t
To determine when 2mg is left in the body
We would have,
A(t) = 2, therefore
2 = 10(0.7)^t
0.7^t =2÷10
0.7^t = 0.2
Take the log of both sides,
Log (0.7)^t = log 0.2
t log 0.7 = log 0.2
t = log 0.2/ 0.7
t = 4.512 hours
Thus it will take 4.512 hours for 2mg to be left in the body.
b) Half life
Let A(t) = 1/2 A(0)
Thus,
1/2 A(0) = A(0)0.7^t
Divide both sides by A(0)
1/2 = 0.7^t
0.7^t = 0.5
Take log of both sides
Log 0.7^t = log 0.5
t log 0.7 = log 0.5
t = log 0.5/log 0.7
t = 1.94 hours
Therefore, the half life of the drug is 1.94 hours
Answer:
12
Step-by-step explanation:
They are the same angle so they must be equal.
So, x+5 = 2x-7
5+7 = 2x-x
12 = x