Triangle ABC is graphed Please solve the following questions given in the picture. Thank you so much!

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

The difference between two numbers is one. three times the larger number minus two times the smaller number is 9. what are the two numbers

George writes the mixed number as sum and uses the distributive property 1/2.-2/5=1/2-2+2/5=1/2