Answer:
A
Step-by-step explanation:
5:9 is the original ratio.
we know that anything times 5 would have the ones place of either 5 or 0 so we can eliminate c and d. Then we test out the other two choices.
25/5=5
45/9=5
A is correct.
15/5=3
45/9=5
Option B is incorrect.
so, the ratio is 25:45
The answer is A!
Area of the shaded region = Area <span>of a square - Area of a circle
</span>
Side of a square = 2r
Area of a square = (2r)² = 4r²
Area of a circle = πr²
Area of the shaded region = 4r² - πr² = <span>r²(4-π)</span>
Answer:

Step-by-step explanation:
Given

Required
Find the equivalent
We start by changing the / to *


Factorize 10a - 5

Expand 4a² - 1


Express (2a)² - 1² as a difference of two squares
Difference of two squares is such that: 
The expression becomes

Combine both fractions to form a single fraction

Divide the numerator and denominator by 2a - 1

Simplify the numerator


Hence,
= 