7. Given the vertices of ∆ABC are A (2,-5), B (-4,6) and C (3,1), find the vertices following each of the transformations FROM THE ORIGINAL vertices: a. Rx = 3 b. T<3,-6> c. r(90◦, o)

Q1)
Rx = 3
in this reflection, the image has been reflected along the x = 3 line. then all the points on the image are reflected along this vertical line. the distance between each point and the vertical line is noted and by that same distance its moved to the opposite side of the vertical line, while the y coordinates stay the same.
A(2,-5)- x coordinate is 2, its 1 unit away from x=3, it should move by 1 unit to the other side of x = 3, then x = 4. y stays as it is.
A' - (4,-5)

B(-4,6) - distance from x = 3, is (-4-+3) is seven units, moves by 7 units to the other side
B' (10,6)

C(3,1) = distance from 3 = 0, therefore the point stays at is,
C' (3,1)

Q2)
next is a translation, in translation the size nor shape changes, each point in the original image moves the same distance in the same direction.
T (3,-6) (x,y) = this means that the x coordinates move by +3 points to the right and y coordinates move downwards by 6 units
A (2,-5) ---> (2+3,-5-6)
A' (5,-11)
B (-4,6) ---> (-4+3,6-6)
B' (-1,0)
C (3,1) ---> (3 + 3, 1-6)
C' (6,-5)

Q3)
r(90°,0)
this is a rotation done in the clockwise direction. then the image takes a rotation to the right direction around the origin. 
then the x, y coordinates of the preimage become ;
(x,y) = (y,-x)
A(2,-5) --> A' = (-5,-2)
B(-4,6) ---> B' = (6,4)
C(3,1)  ---> C' = (1,-3)