The answer is -52
First you must substitute the variables

Then you must simplify

Answer:
D'G' = 52.5 units
Step-by-step explanation:
Since the dilatation is centred at the origin then multiply the original coordinates by the scale factor 3.5
D' = (1 × 3.5, 7 × 3.5 ) = (3.5, 24.5 )
G' = (- 8 × 3.5, - 5 × 3.5 ) = (- 28, - 17.5 )
Calculate D'G' using the distance formula
d = 
with (x₁, y₁ ) = D' (3.5, 24.5) and (x₂, y₂ ) = G' (- 28, - 17.5)
D'G' = 
= 
= 
= 
= 52.5 units
Answer:
20°
Step-by-step explanation:
One way of doing this is to find the constant of proportionality, k:
8k + 6k + 4k = 90° Then 18k = 90°, and k turns out to be 90/18, or 5.
Then the angles are 8(5), 6(5) and 4(5). The smallest of these angles is thus 20°