Plz me with these 4 questions 15-18 about pythagorean theorem.

Which property was used to simplify the expression? 3c+9 +4c=3c+4c+9

Find the simplified product: 2sqrt 5x^3(-3sqrt10x^2) a: -30sqrt2x^5 b: -30x^2sqrt2x c: -12x^2sqrt5x d: -6sqrt50x^5

Suppose you want to transform the graph of the function y=tan(x+pi/4)-1 into the graph of the function y=-tan(x+pi/2)+1 which transformations should you perform. a) reflect the graph of the first function across the x-axis, translate it pi/4 units to the left, and translate it 2 units up. b) reflect the graph of the first function across the x-axis, translate it pi/4 units to the right, and translate it 2 units up. c) reflect the graph of the first function across the line y = -1, translate it pi/4 units to the left, and translate it 2 units up. d) reflect the graph of the first function across the line y = -1, translate it pi/4 units to the right, and translate it 2 units up.