Answer:
Inequality : 4x+8 < 120
x<28
Step-by-step explanation:
Hi, to answer this question we have to apply the next formula:
Perimeter of a rectangle (P)= 2 length +2 width
Where:
Width = x
Length = x+4
Replacing with the values given
P = 2 (x+4) + 2x
P = 2x+8+2x
P=4x+8
Since the perimeter of the rectangle must be less than 120:
4x+8 < 120
Solving for x
4x<120-8
4x<112
x<112/4
x<28
Feel free to ask for more if needed or if you did not understand something.
I believe the answer would be D. Because, 10*12= 120 and 400/120= 3.33
Since you are talking about money, you would round up.
Meaning that the answer should be D.
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
Since he sells 5 large cards for every 2 small, we can multiply the number of small cards he needs to sell by 2.5 to find how many large cards he needs to sell.
So let x=the number of small cards sold, and 2.5x=the number of large cards sold
The equation is:Total profit=x+(2.5x)
Since a small card is $2.5, a large card is $4, and the total profit will be $10,000 plug those in to make the equation:
10,000=2.5x+4(2.5x)
We can combine the x's to get 10,000=12.5x and then divide both sides by 12.5 to get x=800.
So he needs to sell 800 small cards.
Multiply that by that 2.5.
And he needs to sell 2000 large cards.
