PLEASE HELP GUYS/GIRLS

Write the summation to estimate the area under the curve y = 1 + x2 from x = -1 to x = 2 using 3 rectangles and right endpoints

In a two-digit number the units' digit is 7 more than the tens' digit. the number with digits reversed is three times as large as the sum of the original number and the two digits. find the number.

Consider the following equation. 1/2x^3+x-7=-3sqrtx-1 approximate the solution to the equation using three iterations of successive approximation. use the graph below as a starting point. a. b. c. d.