Answer:
D, J
Explanation:
21)
recall for a linear equation in the form
y=mx + b, where m is the slope
the slope a a line that is perpendicular to the equation is given by m' = -1/m
in this case the line is given with the slope of 3/4
hence the slope of a perpendicular line must be,
-1 / (3/4) = -4/3 (Hence D is the answer)
22)
M is the midpoint between Q (a,d) and R (c,b). Using the midpoint formula (see attached), we find the coordinates of M to be:
M [ (a+c)/2 , (d+b)/2 ]
The distance between P(a,b) and M [ (a+c)/2 , (d+b)/2 ] is given by (see other attached formula):
√ [(a+c)/2 - a]² + [(d+b)/2 - b]²
= √ [(a+c)/2 - (2a/2)]² + [(d+b)/2 - (2b/2)]²
= √ [(a+c - 2a)/2]² + [(d+b-2b)/2]²
= √ [(c - a)/2]² + [(d-b)/2]² (J is the answer)