Simplify these expressions a) 5x +3x + 2y + 4y b) 6x - 2x + 8y - 6y

5,600 x 10^3 = a) 560 b) 5,000,600 c) 5,600,000 d) 56,000

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

Pls never taught i’m really confused and i rlly need