Question 9432
Let P= Paul's age now
B = Beth's age now
P-8 = Paul's age 8 years ago
B-8 = Beth's age 8 years ago


First equation, 
P+ B= 67, which means that B = 67 - P


Second equation,
P-8 = 2(B-8)


Substitute the B = 67 - P into the second equation:
P - 8 = 2(B - 8)
P - 8 = 2(67 - P - 8)
P - 8 = 134 - 2P - 16
P - 8 = 118 - 2P


Add + 2P to each side:
P + 2P - 8 = 118 - 2P + 2P
3P - 8 = 118
3P = 126
P = 42  


B= 67 - P
B = 67 - 42
B = 25


Check:  Eight years ago, Paul was 34 and Beth was 17, and Paul was twice as old as Beth.


R^2 at SCC