Jack has n balls, and Tom has n/2 + n/4 balls. If Tom would have 9 balls, how many would Jack have?

Jack has n balls, and Tom has n/2 + n/4 balls. If Tom would have 9 balls, how many would Jack have?

 

n/2 + n/4 = 9            same denominator

2n/4 + n/4 = 9          sums up

3n/4 = 9                   * 4

3n = 36                    /3

n = 12

 

So if Tom would've 9 balls, Jack would then have 12 balls.

x/2 + x/4 = 9

= 3/4

9 * 4/3

= 12

He would have 12 balls 

Tom has 9 balls

and also n/2 + n/4 balls 

so n/2 + n/4 = 9

   (2n + n)/4 = 9

   2n + n = 36

    3n = 36

      n = 12

Jack has n balls

      n = 12

        12 balls