algebra
posted by Sue on .
I need the algebra sentence for the following problem..Adam is 3 times as old as Cynthia and Fred is 16 years younger than Adam. One year ago, Adam's age was twice the sum of Cynthia's and Fred's age.Find their present age.

Let Adam=x, Cynthia=y and Fred=z
We have: x=3y, z=x16 , x1=2(y1+z1)
so x=3y, x=z+16 and x=2y+2z3
3y=z+16 so z=3y16
Also,
3y=2y+2z3 so y=2z3 = 2(3y16)3=6y35 so 5y=35 and y=7, z=3(7)16=5 and x=3(7)=21