Please help with the following problem, i do not understand what I did wrong. For the second part of the question the sum of the left endpoint was 18.9

The rectangles in the graph below illustrate a right endpoint Riemann sum for f(x) = - g + 2x on the interval [3, 7]. The value of this right endpoint Riemann sum is , and it is an there is ambiguity the area of the region enclosed by y = f(x), the x-axis, and the vertical lines x = 3 and x = 7. Right endpoint Riemann sum for y = x52 + 2x on [3, 7] Using the left and right Riemann sums above, we definitively conclude that