X = <span>weight of the baby.
y = </span>weight of the doctor.
z = weight of the nurse.
x + y = 78 so y = 78 - x
x + z = 69 so z = 69 - x
x + y + z = 142
substitute y = 78 - x and z = 69 - x into x + y + z = 142
x + y + z = 142
x +78 - x + 69 - x = 142
-x + 147 = 142
-x = - 5
x = 5
answer
<span>the weight of the baby was 5 kg</span>
Answer:
D. 13*3^x
Step-by-step explanation:
![3^x +4*3^x^+^1= \\3^x+4*3(3^x)=\\3^x(1+[4*3])=\\3^x(1+12)=\\3^x(13)=\\13*3^x](https://tex.z-dn.net/?f=3%5Ex%20%2B4%2A3%5Ex%5E%2B%5E1%3D%20%5C%5C3%5Ex%2B4%2A3%283%5Ex%29%3D%5C%5C3%5Ex%281%2B%5B4%2A3%5D%29%3D%5C%5C3%5Ex%281%2B12%29%3D%5C%5C3%5Ex%2813%29%3D%5C%5C13%2A3%5Ex)
Answer:
Option A.
Step-by-step explanation:
Clarissa needs a $2,500 loan in order to buy a car.
There are 4 options of loan we will calculate all the options that pay the least amount of interest.
To calculate the interest we will use this formula :

Where P = Principal amount
R = rate of interest
T = time in years
A) Principal 2,500 interest 4.75% and time 18 months (1.5 years)

= $178.125
B) Principal 2,500 interest 4% and time 30 months (2.5 years)

= $250
C) Principal 2,500 interest 4.25% and time 24 months (2 years)

= $212.50
D) Principal 2,500 interest 4.50% and time 36 months (3 years)

= $337.50
The least amount of interest would be in option A.
This is a relatively easy half life calculation.
After one half-life period, half of the isotope remains.
After two half-life periods, one quarter of the isotope remains.
That being the case, we see this will take 2 half-life periods or 6 days.