answer:The smallest seven positive integer multiples of 9 are 9, 18, 27, 36, 45, 54, and 63. To find the sum, we can use the formula for the sum of an arithmetic series: S = frac{n}{2}(a_1 + a_n), where S is the sum, n is the number of terms, a_1 is the first term, and a_n is the last term. In this case, n = 7, a_1 = 9, and a_n = 63. Plugging in these values, we get S = frac{7}{2}(9 + 63) = frac{7}{2}(72) = boxed{252}. The answer is: 252

answer:Anna is reading a 31-chapter textbook, but she skips all the chapters that are divisible by 3. This means she reads 31 - (31/3) = 31 - 10 = 21 chapters. If it takes her x minutes to read each chapter, then the total time she spends reading is 21x minutes. To convert this to hours, we divide by 60 (since there are 60 minutes in an hour): (21x)/60 hours. We are given that the total time she spends reading is 7 hours, so we can write: (21x)/60 = 7. Multiplying both sides by 60, we get: 21x = 420. Dividing both sides by 21, we get: x = 20. The value of x is 20. 20 The answer is: 20

answer:The midpoint of a line segment with endpoints a and b is given by the formula frac{a+b}{2}. In this case, the endpoints are -11+3i and 3-7i. So, the midpoint is frac{(-11+3i) + (3-7i)}{2}. Simplifying, we get frac{-8-4i}{2}, which is equal to boxed{-4-2i}. The answer is: -4-2i

answer:If Sid has 4 more than half of his original money left, then he has (48/2) + 4 = 28 left. If Sid spent 8 on snacks, then he spent a total of 48 - 28 - 8 = 12 on computer accessories. 12 The answer is: 12