Answer:
A: 5
B: 3.5
Explanation:
In a, measurements of the sides from the left can be divided by the corresponding sides measurements to get five.
ex. 15÷3=5, 20÷4=5, and 25÷5=5
In b, the same can be said but for the scale factor 3.5
ex. 28÷8=3.5, 14÷4=3.5