Three friends are counting the marbles they’ve collected. Jenny has 10 more than Jack. Jack has 12 more than Jerry. Altogether, the have 52 marbles. How many marbles does each have? Use a variable to solve. Let n be Jack.
Let n be Jack's number of marbles.
Jenny: n + 10
Jack: n
Jerry: n - 12
n + (n + 10) + (n - 12) = 52
Combine like terms: 3n - 2 = 52
Add 2 to both sides: 3n = 54
Divide both sides by 3: n = 18
Jerry: 18 - 12 = <<18-12=6>>6 marbles
Jack: 18 marbles
Jenny: 18 + 10 = <<18+10=28>>28 marbles
Jerry has 6 marbles, Jack has 18 marbles, and Jenny has 28 marbles. Answer: \boxed{6, 18, 28}.