Fraction Question 26 2/3 + (-9 10/15)

Must be in fraction form for answer (please)
Also please explain steps-

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

Here is my question! jayne is studying urban planning and finds that her town is decreasing in population by 3% each year. the population of her town is changing by a constant rate. true or false?

Which angle has the same measure as the dehedral angle formed by the orange face and the purple rectangle