Question 129509
Let x=Mr. Staine's present age

x+4=his age 4 years from now and
x-4=his age 4 years ago

Now we are told that:


(1/2)(x+4)-(3/4)(x-4)=0 simplify

(x/2)+2-(3x/4)+3=0  multiply each term by 4

2x+8-3x+12=0 or
-x+20=0  subtract 20 from each side

-x=-20  divide both sides by -1
x=20-------------------------------------Mr. Staine's present age

CK
(1/2)(20+4)-(3/4)(20-4)=0

12-12=0
0=0


Hope this helps---ptaylor