Question 949792
S=Steven's age; C=Chris's age
S=C+12
S-1=2(C-1) Substitute for S
C+12-1=2C-2 Add 2 to each side,
C+13-2C Subtract C from each side.
13=C ANSWER 1: Chris is 13 years old.
S=C+12=13+12=25 ANSWER 2: Steven is 25 years old.
CHECK
S-1=2(C-1)
25-1=2(13-1)
24=2(12)
24=24