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.