You can write an expression for this: 290,000 = (2x+35000) + x. So simplify: 290,000 = 3x + 35000... 255,000 = 3x. So x is equal to 85,000 which is equal to the attendance of Bonnaroo. Plugin this into the 2x + 35000 equation and the attendance at Lollapalooza is 205,000.