Question 140752
Let x=her son's age now
then x-1=her son's age one year ago

x+18=Zelma's age now
and x+17=Zelma's age 1 year ago

Now we are told the following:
------she was three times as old as he was (her son) one year ago-----

x+17=3(x-1)  get rid of parens (distributive)

x+17=3x-3  subtract 3x and also 17 from each side

x+17-17-3x=3x-3x-3-17  collect like terms

-2x=-20 divide each side by -2
x=10-------------------------------------her son's age now

x+18=10+18=28---------------------------------Zelma's age now

CK
-----------zelma is eighteen years older than her son-----
10+18=28
28=28
------she was three times as old as he was (her son) one year ago-----

10+17=3(10-1)
27=3*9
27=27



Hope this helps---ptaylor