S = sally C = Chris J = Joe
sally is one year older than 3 times the age of joe, so
s = 3j + 1
chris is 5 years younger than 6 times the age of jo, so
c = 6j - 5
sally and chris are the same age so
s = c so
3j + 1 = 6j - 5
-3j -3j
1 = 3j - 5
+5 +5
6 = 3j or
3j = 6
3j/3 = 6/3
j = 2
check
s = c
3(2) +1 = 6(2) - 5
6 + 1 = 12 - 5
7 = 7 correct✅
