bonjour

4 x + 2 = 30

4 x = 28

x = 7

Alice = 3 x + 4

Tom = 2 x + 7

3 x + 4 = 2 x + 7

3 x - 2 x = 3

x = 3

Laura = x

Jim = x /3

Arthur =  2 ( x + x /3 )  = 2 x + 2 x /3

x + x /3 + 2 x + 2 x /3 = 24

3 x /3 + x /3 + 6 x /3 + 2 x /3 =  72 /3

12 x = 72

x = 6

Laura = 6

Jim =  2

Arthur  =  2 * 8 = 16