A roofing contractor buys 30 bundles of shingles and 4 rolls of roofing paper for $1040. In a second purchase (at the same prices) the contractor buys 12 bundles of shingles and 16 rolls of roofing paper for $2000. Create and solve a system of equations in order to determine how much each bundle of shingles (x) and roll of roofing paper (y) would cost