Determine how many cards, in an ordinary deck of fifty-two, fit the description. 4's and 5's

The parabola opens: y=√x-4 (principal square root) up down right left

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

What is the approximate value of  x  in the equation below.–3.396–0.7080.3040.955