List the factors of 24,30, and 24. Factors of 24: 1,2,3,4,6,8,12,24. Factors of 30: 1,2,3,5,6,10,15,30. Factors of 42: 1,2,3,6,7,14,21,42. The highest number that all of these numbers is 6. Therefore, the greatest common factor of GCF of 24,30, and 42 is 6.
Your answer is B. 2 This is because to rationalise the denominator, we need to multiply it by (3 - √7), so we get: (3 + √7)(3 - √7) 3 × 3 = 9 3 × √7 = 3√7 3 × -√7 = -3√7 √7 × -√7 = -7 So all in all you get 9 - 7 which is 2.
