Western State College is 18 years older than Southern State. Western is also 2 1/2 times as old as Southern. How old is each?

1 Answer
Mar 5, 2018

western =

Explanation:

use the variable w to represent the age of western state
use the variable s to represent the age of southern state

we need to write 2 equation because we have 2 variables

we know that western state is 18 years older than southern state
w=18+s

western state is 2.5 times as old as southern
w=2.5s

solve the system of equations

because 18+s and 2.5s are both equal to w, they are also equal to each other
18+s=2.5s

solve for s by subtracting s from both sides, then dividing by 1.5
18=1.5s
12=s

plug in 12 for s in the first equation
w=18+12
w=30