What is the solution to this system of equations? -5.9x-3.7y=-2.1 and 5.9x+3.7y=2.1 A (0,-2.1)
B (0,2.1)
C infinitely many
D solutions no solution

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