30 + 1.8x = 264 x = 130 First, the expression. "Marni raised $30 plus $1.80 per minute" that gives us 30 + 1.8x = ? "She raised a total of $264", which gives us 30 + 1.8x = 264 And that expression is the 1st answer. Now solve for x 30 + 1.8x = 264 1.8x = 264 - 30 = 234 x = 130 So Marni danced for 130 minutes.