Question 177558
let r and p be the charge per hour of regular and premium services, respectively
:
9r+2p=28......eq 1
6r+3p=27......eq 2
:
multiply eq 1 by -3 and eq 2 by 2 and add the equations together
:
-27r-6p=-84...revised eq 1
12r+6p=54.....revised eq 2
:
you can see that the p terms are eliminated because -6p+6p=0. We are left with
 -27r+12r=-84+54
:
-15r=-30
:
${{{highlight(r=2)}}}per hour for regular
:
now take r's found value and plug it into either eq 1 or 2. I chose eq 2
:
9(2)+2p=28
:
2p=10
:
${{{highlight(p=5)}}}per hour for premium