Answers

2015-12-10T21:33:41+08:00
Sol. let x  be the number of girls
            y be the number of boys

           x + y = 45
           y = x + 9
        x + x + 9 = 45
         2x = 45 - 9
         2x = 36     or x = 18
   Therefore : girls = 18
                     boys = 27
      

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2015-12-12T15:46:36+08:00
Let x = no. of girls
x + 9 = no. of boys

x + x + 9 = 45
    2x + 9 = 45
2x + 9 -9 = 45 - 9
         2x  = 36
    2x ÷ 2 = 36 ÷ 2
            x = 18 - no. of girls
      x + 9 = 27 - no. of boys
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