Answer:
D
Step-by-step explanation:
She spent $12 and *$ on two separate things, meaning she spent $20 on both.
So, 12 + 8 = 20.
If she started with 25, we subtract 20 from 25 to get how much she has left.
So, 25 - 20 = y.
Therefore, the answer is D.
Answer:
(0, 4)
Step-by-step explanation:
The y-intercept is the y-value when x = 0.
From the graph, we see that when x = 0, y = 4.
Answer:
After 80 years 432 pounds of radioactive element will be remaining.
Step-by-step explanation:
A function
models the amount of a radioactive material.
Here x = number of years taken for decay.
If
pound and
pound, then we have to calculate the time for decay.


Take log on both the sides of the equation

-0.0077x = ln(0.54)
-0.0077x = -0.616186
x = 
x = 80.02 years
Therefore, After 80 years 432 pounds of radioactive element will be remaining.
This is not a full question. If you were given the amount at the begining of 1970 (we'll call it x) and the amount at the end of 1980 (we'll call it y), we should solve them accordingly:
y-x=? (calling the answer a)
a/y=%(not answer yet, call this b)
b+100=answer
Answer:
186 (in²) and 230 (cm²).
Step-by-step explanation:
All the details find in the attachment.