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Seven years ago, Grogg's dad was $9$ times as old as Grogg. Four years ago, Grogg's dad was $6$ times as old as Grogg. How old is Grogg's dad currently?

 Apr 1, 2024
 #1
avatar+128399 
+1

9  ( G - 7)  =  D - 7    →  9G - 63  = D - 7  →  9G = D + 56     (1) 

 

6 ( G - 4)  = D - 4     →  6G  - 24  = D - 4  →  6G  =  D + 20    (2)

 

Multiply   (2)  by 1.5

9G = 1.5D + 30     (3)

 

Set ( 1)  = (3)

 

1.5D  + 30  =  D + 56

 

.5D  = 26

 

(1/2)D =  26               mult both sides by 2

 

D =  52

 

cool cool cool

 Apr 1, 2024

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