SOLUTION: Sandy's age is three times Tom's age. Four years from now, Sandy will be twice as old as Tom. How old is Sandy now?

Algebra ->  Coordinate Systems and Linear Equations -> SOLUTION: Sandy's age is three times Tom's age. Four years from now, Sandy will be twice as old as Tom. How old is Sandy now?      Log On


   

Question 979080: Sandy's age is three times Tom's age. Four years from now, Sandy will be twice as old as Tom. How old is Sandy now?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
(1) +s+=+3t+
(2) +s+%2B+4+=+2%2A%28+t+%2B+4+%29+
-----------------------
Substitute (1) into (2)
(2) +3t+%2B+4+=+2t+%2B+8+
(2) +t+=+4+
and
(1) +s+=+3t+
(1) +s+=+3%2A4+
(1) +s+=+12+
----------------
Sandy is 12 now
check:
(2) +s+%2B+4+=+2%2A%28+t+%2B+4+%29+
(2) +12+%2B+4+=+2%2A%28+4+%2B+4+%29+
(2) +16+=+2%2A8+
(2) +16+=+16+
OK