A = (a+b)/2
2*A = 2*(a+b)/2 ... multiply both sides by 2
2A = a+b
2A-a = a+b-a ... subtract 'a' from both sides to isolate b
2A-a = b
b = 2A-a
Answer: b = 2A-a
Less by far because 3.5 cups would be less than half
Answer:
Exponential
Step-by-step explanation:
<em>Starter:</em>
According to the title:
"Every day, half a bacteria population dies."
Exponential: y = ab^x ( b > 0 , b ≠ 1)
So the answer is C.
<em>Calculations:</em>
An exponential model is of the form y = a • b^t.
If you start with population of 500 million bacteria
t = 0
so 500 million = a • b^0 = a
Since every day half the population dies then in 1 day population will be 250 million
so a = 500 million, y = 250 million and t = 1
250 million = 500 million • b^1
b = 0.5
Therefore your equation would be
y = 500 million (or whatever the pop) • 0.5^t
Where t = number of days
This could also be written in exponential form ( e = 2.73)
Let the number of gallons consumed be the first car be x, and that of the second car, y. Then:
x + y = 50 . . . . . . . (1)
20x + 15y = 850. . . (2)
(1) x 20 => 20x + 20y = 1000 . . . (3)
(2) - (3) => -5y = -150 => y = -150/-5 = 30
From (1), x + 30 = 50 => x = 50 - 30 = 20
Therefore, first car consumed 20 gallons and the second consumed 30 gallons.
