Solve this inequality:
-12a +7<31

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

Which expression gives the exact value of x?

y=2x−1 5x−4y=1 is (1,1)(1,1) a solution of the system?