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=x-16 , x-1=2(y-1+z-1)
so x=3y, x=z+16 and x=2y+2z-3
3y=z+16 so z=3y-16
3y=2y+2z-3 so y=2z-3 = 2(3y-16)-3=6y-35 so 5y=35 and y=7, z=3(7)-16=5 and x=3(7)=21