karen (k) is (=) 7 years older (+7) than suzanne(s) k=7+s
four year ago means s-4 and k-4
four years ago (-4 to all) karen (k) was (=) twice (2 times) suzzane (s) k-4=2(s-4) distribute k-4=2s-8 add 4 to both sides k=2s-4 we know that k=7+s so subsitute 7+s for k 7+s=2s-4 add 4 to both sides 11+s=2s subtract s from both sides 11=s