Find the radius for the following problems, help I don’t understand :(

Use continuity to evaluate the limit. lim x→16 20 + x 20 + x step 1 consider the intervals for which the numerator and the denominator are continuous. the numerator 20 + x is continuous on the interval the denominator 20 + x is continuous and nonzero on the interval

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

What else equals 42 and 30 for multiply