Answer: 
Step-by-step explanation:
Since the center of dilation is not at the origin, we can use the following formula in order to find the coordinates of the vertices of the triangle D'E'F':

Where "O" is the center of dilation at (a,b) and "k" is the scale factor.
In this case you can identify that:

Therefore, susbtituting values into the formula shown above, you get that the coordinates ot the resulting triangle D'E'F, are the following:
Vertex D' → 
Vertex E' → 
Vertex F' → 
Answer:
Step-by-step explanation:
Area of the trapezoid = area of rectangle + 2 * area of triangle
Area of a triangle = 1/2 bh
= 1/2 * 13 * 7
= 45.5 units²
Area of a rectangle = L × B
= 15 × 13
= 195 units²
Area of the trapezoid = [195 + 2 * (45.5)]
= 195 + 91
= 286 units²
Answer:
-63/2
Step-by-step explanation:
6( -5 1/4)
= 6(-21/4)
= -63/2