Is 2 times the square root of 3 times 2 times the square root of 6 rational

Is the square root of 4 plus the square root of 16 rational?

List x1, x2, x3, x4 where xi is the left endpoint of the four equal intervals used to estimate the area under the curve of f(x) between x = 4 and x = 6. a 4, 4.5, 5, 5.5 b 4.5, 5, 5.5, 6 c 4.25, 4.75, 5.25, 5.75 d 4, 4.2, 5.4, 6

Given abc find the values of x and y. in your final answer, include all of your calculations.