28) Slope is (5-2)/(-2-4) = 3/-6 = -1/2 so a possible point-slope form is
y - 2 = -1/2(x-4)
29) y = -2 is a horizontal line. If you are wanting a line perp. to a horizontal line, you get a vertical line of the form x = a. Since it passes through (-2,-1), the point slope form is just x = -2 (there's no real point slope form because there is no y. vertical line does not care about y; all the y-values are on the vertical line)
30) Since 25*3 = 75, √(75) = √(25*3)=√25 * √3 = 5√3
31) √128 = √(64 * 2) = 8√2
32) √144 = 12 because 12*12 = 144
33) 4√(54) = 4√(9*6) = 12√6
34) 2√(32) = 2√(16*2) = 8√2
35) -6√175 = -6√(25*7) = -30√7