We know that the original width was 5, and that after the enlargement the width is 45. To calculate the scale factor we divide the final width between the original one, then:

Therefore the scale factor is 9.
I am using the laws:
1)

2)

3)

an x is a base - the law is valid if the bases are the same number!
The solution in attachment :)
Answer:
Option (B) 5.1 units
Step-by-step explanation:
Since the radius of the circle is half of its diameter and given the diameter of the circle is 10.2 units then the radius would be 
Thus the answer.
They tell you that the length is 7 inches and that it is 2 inches more than the width therefore you can conclude that: length = 7 and the width = 5
you can plug the values given into the formula listed below:
A = lw
A = 7 x 5
A = 35
hope this helps :)