7p + 8p -12 = 59 cans someone me on this

Which of the following is the result of expanding the series

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

Solve the following pair of equations for x and y: ax/b_ by /a= a +b; ax - by = 2ab