Answer:
value of a in terms of b and c is: 
Option D is correct.
Step-by-step explanation:
We are given:

We need to find a in terms of b and c
We have: 
Put value of d 

So, value of a in terms of b and c is: 
Option D is correct.
Answer:
3800 +/-10
Step-by-step explanation:
Answer:
The age of each person is:
- Jess is <u>21</u> years old.
- Mac is <u>66</u> years old.
Step-by-step explanation:
To solve this problem you must make two equations. First, we name Jess and Mac as variables:
j = Jess age.
m = Mac age.
Now we make the equations, the first equation has the information "Jess is 12 years less than half as old as Mac":
1. 
The second equation has the information "The sum of their age is 87":
2. 
Now, we replace the first equation in the second one:
And we operate:
We clear the variable m:
How we know Mac's age is 66 years old, we can identify Jess' age with the second equation:
We replace the value of m:
And clear the variable j:
In the end, Jess's age is 21 years old.
21/100 is the answer. Hope this helped!
22.
Alternate angles23.
4: (

, substitute b with 10 and a with 20 and you get 4.)
24.
0.28: 0.12 + 0.60 = 0.72. Probability is always out of 1, so 1 - 0.72 should give you the probability of losing, which is 0.28.