Answer:
Step-by-step explanation:
If we let A, C, and J represent the number of stickers collected by Ann, Clair, and Josh. respectively, then we have the relations ...
A = J +7
J = 2C
A + C + J = 157
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Substituting the first equation into the last, we have ...
J +7 + C + J = 157
C +2J = 150 . . . . . . . collect terms, subtract 7
Substituting the second equation into this one, we have ...
C +2(2C) = 150
C = 150/5 = 30 . . . . divide by the coefficient of C
J = 2·30 = 60
A = 60 +7 = 67
Ann collected 67 stickers, Clair collected 30, and Josh collected 60 stickers.
