Question 877645:  Grace is three years younger then her sister Jane. Twice the sum of their ages is 4 more 
than their father’s age. If their father is 54, find the ages of Grace and Jane 
 Answer by ankor@dixie-net.com(22740)      (Show Source): 
You can  put this solution on YOUR website! let g = G's age 
let j = J's age 
: 
Write an equation for each statement 
: 
Grace is three years younger then her sister Jane. 
g = j - 3 
or 
g - j = -3 
: 
 Twice the sum of their ages is 4 more than their father’s age. 
 If their father is 54, find the ages of Grace and Jane 
2(g+j) = 54 + 4 
2g + 2j = 58 
simplify, divide by 2, then add the 1st equation 
g + j = 29 
g - j = -3 
-------------adding eliminates j, find g 
2g = 26 
g = 13 yrs is G's age 
then 
13 = j - 3 
j = 16 is J's age 
  | 
 
  
 
 |   
 
 |