Answer:
#1. 40
#2. y=221.5
#3 197 ft
#4. 30 min
Step-by-step explanation:
Answer: Option 'B' is correct.
Step-by-step explanation:
Let the initial concentration be
Let concentration after t= 90 hours be N
Since we have given that Sodium-24 has a half life of 15 hours i.e.
So, According to question,
As we know that
Hence, Option 'B' is correct.
Answer:
x = $2.56
Step-by-step explanation:
To solve this, you do the inverse of both operations, which is multiplication and subtraction. The first inverse would be addition, so 2.81 + 2.31 = 5.12. Then, the second inverse would be division, so 5.12 divided by 2 = 2.56. So therefore, x = $2.56 is the correct answer for the price in September 2006.
Answer:
10 ft by 12 ft
Step-by-step explanation:
This problem requires you to first write an equation to represent the situation. Here we will represent the shorter side of the doghouse with the variable x, the longer side will be represented with x+2 because it is 2 feet longer.
48 = x * (x+2)
This represents the area of the doghouse as the product of the width and length of the doghouse.
48 = x^2 + 2x
Now, we need to move all the items onto one side of the equals sign, it is best to have the x^2 be positive.
0 = x^2 + 2x - 48
Now, we factor to find what x equals.
0 = (x-6) * (x+8)
From here, we can use each of the terms in parentheses to solve for x.
0 = x-6
x = 6
0 = x+8
0 = -8
Here we know that the shorter side has to be 6 ft because length is a positive number, and we can determine that the longer side is 8 ft because it is 2 ft longer. The dimensions of the slab are therefore 10 ft by 12 ft because the slab is 2 ft on each side, therefore adding an extra 4ft to the dimensions because the 2ft is added on each side.
