Factor completely (x2 + x - 6)(2x2 + 4x)

Standard deviation of 19,29,21,22,23

The length of a rectangular board is 3 feet less than twice its width. a second rectangular board is such that each of its dimensions is the reciprocal of the corresponding dimensions of the first rectangular board. if the perimeter of the second board is one-fifth the perimeter of the first, what is the perimeter of the first rectangular board?  

The ratio of the ages (in years) of three children is 2: 4: 5. the sum of their ages is 33. what is the age of each child?