Tell whether each equation has one solution, infinitely many solutions, or no solution.

6x + 8 = 6(x + 2)
10x = 15 + 5x
x + 11 = 8x + 11 - 7x

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