The scale factor is the first choice, 5/9.
This is because if you multiply 18 x 5/9, You get 10.
Answer:
5/9
Step-by-step explanation:
Ask yourself: How do you get from 18 to 10?
Multiplying 18 by 5/9 will do the trick:
5 5(2)
---- · 18 = -------- after reducing 18/9
9 1
This comes out to 10, showing that the correct scale factor is 5/9.