The equation will be of the form:

where A is the amount after t hours, and r is the decay constant.
To find the value of r, we plug the given values into the equation, giving:

Rearranging and taking natural logs of both sides, we get:


The required model is:
Answer:
1/6
Step-by-step explanation:
-3/4 - (-1/2) = - 1/4
-2/3 - 5/6 = - 3/2
-1/4 ÷ -3/2
Answer:
a = 30
b = 40
C
Step-by-step explanation:
This requires that you use a proportion.
a / (a + 15) = 40 / 60
The small triangle's sides are in proportion to the large triangles sides.
Reduce the right. Divide top and bottom by 20
a/(a + 15) = 40/20 // 60/20
a/(a + 15) = 2/3
Cross multiply
3a = 2(a + 15) Remove the brackets on the right.
3a = 2a + 30
Subtract 2a from both sides
3a-2a = 30
a = 30
Find B
b is done exactly the same way.
b/(b+20) = 2/3
3b = 2b + 40
3b - 2b = 40
b = 40
Answer:
The vertex form is y = (x + 4)² - 13
The minimum value of the function is -13
Step-by-step explanation:
∵ y = x² + 8x + 3
∵ 8x ÷ 2 = 4x ⇒ (x) × (4)
∴ We need ⇒ x² + 8x + 16 to be completed square
∴ y = (x² + 8x + 16) - 16 + 3 ⇒ we add 16 and subtract 16
∴ y = (x + 4)² - 13 ⇒ vertex form
∵ The vertex form is (x - a)² + b
Where a is the x-coordinate of the minimum point and b is y-coordinate of the minimum point (b is the minimum value of the function)
∴ The minimum value is -13
Answer:
70%
Step-by-step explanation:
21/30 * 100 = 70%