Solve this problem???​

The denominator of the first term is a difference of squares, such that

4a ² - b ² = (2a)² - b ² = (2a - b) (2a + b)

So you can write the fractions as

(4a ² + b ²)/((2a - b) (2a + b)) - (2a - b)/(2a + b)

Multiply through the second fraction by 2a - b to get a common denominator:

(4a ² + b ²)/((2a - b) (2a + b)) - (2a - b)²/((2a + b) (2a - b))

((4a ² + b ²) - (2a - b)²) / ((2a - b) (2a + b))

Expand the numerator:

(4a ² + b ²) - (2a - b)²

(4a ² + b ²) - (4a ² - 4ab + b ²)

4ab

So the original expression reduces to

4ab / ((2a - b) (2a + b))

or

4ab / (4a ² - b ²)

upon condensing the denominator again.